165222561 has 24 divisors (see below), whose sum is σ = 257931840. Its totient is φ = 93798432.

The previous prime is 165222553. The next prime is 165222569.

165222561 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (165222553) and next prime (165222569).

It is not a de Polignac number, because 165222561 - 2³ = 165222553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165222569) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19500 + ... + 26658.

It is an arithmetic number, because the mean of its divisors is an integer number (10747160).

Almost surely, 2^165222561 is an apocalyptic number.

It is an amenable number.

165222561 is a deficient number, since it is larger than the sum of its proper divisors (92709279).

165222561 is a wasteful number, since it uses less digits than its factorization.

165222561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7333 (or 7326 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 165222561 is about 12853.8928344685. The cubic root of 165222561 is about 548.7271513223.

The spelling of 165222561 in words is "one hundred sixty-five million, two hundred twenty-two thousand, five hundred sixty-one".