165563920 has 20 divisors (see below), whose sum is σ = 384936300. Its totient is φ = 66225536.

The previous prime is 165563917. The next prime is 165563933. The reversal of 165563920 is 29365561.

It can be written as a sum of positive squares in 2 ways, for example, as 116899344 + 48664576 = 10812^2 + 6976^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a super-2 number, since 2×165563920² = 54822823211532800, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 165563920.

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 3 ways as a sum of consecutive naturals, for example, 1034695 + ... + 1034854.

It is an arithmetic number, because the mean of its divisors is an integer number (19246815).

Almost surely, 2^165563920 is an apocalyptic number.

165563920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165563920 is an abundant number, since it is smaller than the sum of its proper divisors (219372380).

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

165563920 is a wasteful number, since it uses less digits than its factorization.

165563920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2069562 (or 2069556 counting only the distinct ones).

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 165563920 is about 12867.1644117886. The cubic root of 165563920 is about 549.1047916371.

The spelling of 165563920 in words is "one hundred sixty-five million, five hundred sixty-three thousand, nine hundred twenty".