165561051 has 16 divisors (see below), whose sum is σ = 231993344. Its totient is φ = 104890464.

The previous prime is 165561043. The next prime is 165561089. The reversal of 165561051 is 150165561.

It is not a de Polignac number, because 165561051 - 2³ = 165561043 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165561001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12571 + ... + 22116.

It is an arithmetic number, because the mean of its divisors is an integer number (14499584).

Almost surely, 2^165561051 is an apocalyptic number.

165561051 is a deficient number, since it is larger than the sum of its proper divisors (66432293).

165561051 is a wasteful number, since it uses less digits than its factorization.

165561051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34770.

The product of its (nonzero) digits is 4500, while the sum is 30.

The square root of 165561051 is about 12867.0529259811. The cubic root of 165561051 is about 549.1016198697.

The spelling of 165561051 in words is "one hundred sixty-five million, five hundred sixty-one thousand, fifty-one".