660644231 has 8 divisors (see below), whose sum is σ = 748908720. Its totient is φ = 577729152.

The previous prime is 660644219. The next prime is 660644251. The reversal of 660644231 is 132446066.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 660644231 - 2²⁶ = 593535367 is a prime.

It is a super-2 number, since 2×660644231² = 872901599907162722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660644251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1337090 + ... + 1337583.

It is an arithmetic number, because the mean of its divisors is an integer number (93613590).

Almost surely, 2^660644231 is an apocalyptic number.

660644231 is a deficient number, since it is larger than the sum of its proper divisors (88264489).

660644231 is a wasteful number, since it uses less digits than its factorization.

660644231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2674705.

The product of its (nonzero) digits is 20736, while the sum is 32.

The square root of 660644231 is about 25703.0004279656. Note that the first 3 decimals coincide. The cubic root of 660644231 is about 870.9419625351.

The spelling of 660644231 in words is "six hundred sixty million, six hundred forty-four thousand, two hundred thirty-one".