165565457 has 4 divisors (see below), whose sum is σ = 166581360. Its totient is φ = 164549556.

The previous prime is 165565429. The next prime is 165565469. The reversal of 165565457 is 754565561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 754565561 = 317 ⋅2380333.

It is a cyclic number.

It is not a de Polignac number, because 165565457 - 2¹⁰ = 165564433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165565357) by changing a digit.

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, 507707 + ... + 508032.

It is an arithmetic number, because the mean of its divisors is an integer number (41645340).

Almost surely, 2^165565457 is an apocalyptic number.

It is an amenable number.

165565457 is a deficient number, since it is larger than the sum of its proper divisors (1015903).

165565457 is a wasteful number, since it uses less digits than its factorization.

165565457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1015902.

The product of its digits is 630000, while the sum is 44.

The square root of 165565457 is about 12867.2241373188. The cubic root of 165565457 is about 549.1064908227.

The spelling of 165565457 in words is "one hundred sixty-five million, five hundred sixty-five thousand, four hundred fifty-seven".