165645818640 has 160 divisors (see below), whose sum is σ = 582697704960. Its totient is φ = 43232357376.

The previous prime is 165645818627. The next prime is 165645818647. The reversal of 165645818640 is 46818546561.

It is a happy number.

165645818640 is a `hidden beast` number, since 1 + 6 + 5 + 6 + 458 + 186 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (165645818647) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 714309 + ... + 917348.

It is an arithmetic number, because the mean of its divisors is an integer number (3641860656).

Almost surely, 2^165645818640 is an apocalyptic number.

165645818640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165645818640 is an abundant number, since it is smaller than the sum of its proper divisors (417051886320).

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

165645818640 is a wasteful number, since it uses less digits than its factorization.

165645818640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1631726 (or 1631714 counting only the distinct ones).

The product of its (nonzero) digits is 5529600, while the sum is 54.

The spelling of 165645818640 in words is "one hundred sixty-five billion, six hundred forty-five million, eight hundred eighteen thousand, six hundred forty".