661275231 has 16 divisors (see below), whose sum is σ = 974156544. Its totient is φ = 396877184.

The previous prime is 661275227. The next prime is 661275233. The reversal of 661275231 is 132572166.

It is a cyclic number.

It is not a de Polignac number, because 661275231 - 2² = 661275227 is a prime.

It is a super-2 number, since 2×661275231² = 874569862268206722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661275192 and 661275201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661275233) 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, 280701 + ... + 283046.

It is an arithmetic number, because the mean of its divisors is an integer number (60884784).

Almost surely, 2^661275231 is an apocalyptic number.

661275231 is a deficient number, since it is larger than the sum of its proper divisors (312881313).

661275231 is a wasteful number, since it uses less digits than its factorization.

661275231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563790.

The product of its digits is 15120, while the sum is 33.

The square root of 661275231 is about 25715.2723298821. The cubic root of 661275231 is about 871.2191614051.

The spelling of 661275231 in words is "six hundred sixty-one million, two hundred seventy-five thousand, two hundred thirty-one".