165563388 has 18 divisors (see below), whose sum is σ = 418507544. Its totient is φ = 55187784.

The previous prime is 165563369. The next prime is 165563389. The reversal of 165563388 is 883365561.

165563388 is a `hidden beast` number, since 1 + 6 + 5 + 5 + 633 + 8 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×165563388² = 54822470892077088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165563389) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2299456 + ... + 2299527.

Almost surely, 2^165563388 is an apocalyptic number.

165563388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

165563388 is an abundant number, since it is smaller than the sum of its proper divisors (252944156).

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

165563388 is a wasteful number, since it uses less digits than its factorization.

165563388 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4598993 (or 4598988 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The square root of 165563388 is about 12867.1437389966. The cubic root of 165563388 is about 549.1042034976.

The spelling of 165563388 in words is "one hundred sixty-five million, five hundred sixty-three thousand, three hundred eighty-eight".