123161640 has 128 divisors (see below), whose sum is σ = 425502720. Its totient is φ = 27936000.

The previous prime is 123161639. The next prime is 123161653. The reversal of 123161640 is 46161321.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 123161640.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 126355 + ... + 127325.

It is an arithmetic number, because the mean of its divisors is an integer number (3324240).

Almost surely, 2^123161640 is an apocalyptic number.

123161640 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 123161640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212751360).

123161640 is an abundant number, since it is smaller than the sum of its proper divisors (302341080).

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

123161640 is a wasteful number, since it uses less digits than its factorization.

123161640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1143 (or 1139 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 123161640 is about 11097.8214078260. The cubic root of 123161640 is about 497.5367379417.

The spelling of 123161640 in words is "one hundred twenty-three million, one hundred sixty-one thousand, six hundred forty".