655665231 has 16 divisors (see below), whose sum is σ = 996849504. Its totient is φ = 379751424.

The previous prime is 655665229. The next prime is 655665239. The reversal of 655665231 is 132566556.

It is not a de Polignac number, because 655665231 - 2¹ = 655665229 is a prime.

It is a super-2 number, since 2×655665231² = 859793790284566722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 655665231.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (655665239) 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, 493806 + ... + 495131.

It is an arithmetic number, because the mean of its divisors is an integer number (62303094).

Almost surely, 2^655665231 is an apocalyptic number.

655665231 is a deficient number, since it is larger than the sum of its proper divisors (341184273).

655665231 is a wasteful number, since it uses less digits than its factorization.

655665231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 988970.

The product of its digits is 162000, while the sum is 39.

The square root of 655665231 is about 25605.9608489898. The cubic root of 655665231 is about 868.7484673575.

The spelling of 655665231 in words is "six hundred fifty-five million, six hundred sixty-five thousand, two hundred thirty-one".