1665920 has 64 divisors (see below), whose sum is σ = 4222800. Its totient is φ = 626688.

The previous prime is 1665919. The next prime is 1665929. The reversal of 1665920 is 295661.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12092 + ... + 12228.

2^1665920 is an apocalyptic number.

1665920 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 1665920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2111400).

1665920 is an abundant number, since it is smaller than the sum of its proper divisors (2556880).

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

1665920 is a wasteful number, since it uses less digits than its factorization.

1665920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 29.

The square root of 1665920 is about 1290.7052335836. The cubic root of 1665920 is about 118.5454020806.

The spelling of 1665920 in words is "one million, six hundred sixty-five thousand, nine hundred twenty".