165621543560 has 32 divisors (see below), whose sum is σ = 406525608000. Its totient is φ = 60226015680.

The previous prime is 165621543559. The next prime is 165621543569. The reversal of 165621543560 is 65345126561.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (165621543569) 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, 188205860 + ... + 188206739.

It is an arithmetic number, because the mean of its divisors is an integer number (12703925250).

Almost surely, 2^165621543560 is an apocalyptic number.

165621543560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165621543560 is an abundant number, since it is smaller than the sum of its proper divisors (240904064440).

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

165621543560 is a wasteful number, since it uses less digits than its factorization.

165621543560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 376412621 (or 376412617 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 44.

The spelling of 165621543560 in words is "one hundred sixty-five billion, six hundred twenty-one million, five hundred forty-three thousand, five hundred sixty".