664785231 has 32 divisors (see below), whose sum is σ = 986802432. Its totient is φ = 394709760.

The previous prime is 664785211. The next prime is 664785269. The reversal of 664785231 is 132587466.

It is not a de Polignac number, because 664785231 - 2⁷ = 664785103 is a prime.

It is a super-2 number, since 2×664785231² = 883878806711446722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664785211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 391821 + ... + 393513.

It is an arithmetic number, because the mean of its divisors is an integer number (30837576).

Almost surely, 2^664785231 is an apocalyptic number.

664785231 is a deficient number, since it is larger than the sum of its proper divisors (322017201).

664785231 is a wasteful number, since it uses less digits than its factorization.

664785231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943.

The product of its digits is 241920, while the sum is 42.

The square root of 664785231 is about 25783.4293878840. The cubic root of 664785231 is about 872.7578977248.

The spelling of 664785231 in words is "six hundred sixty-four million, seven hundred eighty-five thousand, two hundred thirty-one".