166565553 has 48 divisors (see below), whose sum is σ = 283668480. Its totient is φ = 85965600.

The previous prime is 166565513. The next prime is 166565569. The reversal of 166565553 is 355565661.

It is a de Polignac number, because none of the positive numbers 2^k-166565553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166565513) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 386248 + ... + 386678.

It is an arithmetic number, because the mean of its divisors is an integer number (5909760).

Almost surely, 2^166565553 is an apocalyptic number.

It is an amenable number.

166565553 is a deficient number, since it is larger than the sum of its proper divisors (117102927).

166565553 is a wasteful number, since it uses less digits than its factorization.

166565553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698 (or 691 counting only the distinct ones).

The product of its digits is 405000, while the sum is 42.

The square root of 166565553 is about 12906.0277777479. The cubic root of 166565553 is about 550.2098956452.

The spelling of 166565553 in words is "one hundred sixty-six million, five hundred sixty-five thousand, five hundred fifty-three".