165564978 has 16 divisors (see below), whose sum is σ = 333240960. Its totient is φ = 54836496.

The previous prime is 165564977. The next prime is 165564983. The reversal of 165564978 is 879465561.

165564978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 165564978.

It is not an unprimeable number, because it can be changed into a prime (165564977) 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, 86938 + ... + 88821.

It is an arithmetic number, because the mean of its divisors is an integer number (20827560).

Almost surely, 2^165564978 is an apocalyptic number.

165564978 is an abundant number, since it is smaller than the sum of its proper divisors (167675982).

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

165564978 is a wasteful number, since it uses less digits than its factorization.

165564978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175921.

The product of its digits is 1814400, while the sum is 51.

The square root of 165564978 is about 12867.2055241222. The cubic root of 165564978 is about 549.1059612793.

The spelling of 165564978 in words is "one hundred sixty-five million, five hundred sixty-four thousand, nine hundred seventy-eight".