165428640 has 144 divisors (see below), whose sum is σ = 608019048. Its totient is φ = 40716288.

The previous prime is 165428633. The next prime is 165428657. The reversal of 165428640 is 46824561.

165428640 is a `hidden beast` number, since 1 + 6 + 5 + 4 + 2 + 8 + 640 = 666.

165428640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 153066384 + 12362256 = 12372^2 + 3516^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 165428595 and 165428604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14302 + ... + 23138.

Almost surely, 2^165428640 is an apocalyptic number.

165428640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165428640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (304009524).

165428640 is an abundant number, since it is smaller than the sum of its proper divisors (442590408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165428640 is a wasteful number, since it uses less digits than its factorization.

165428640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8871 (or 8860 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 165428640 is about 12861.9065460763. The cubic root of 165428640 is about 548.9551955632.

The spelling of 165428640 in words is "one hundred sixty-five million, four hundred twenty-eight thousand, six hundred forty".