664235646 has 16 divisors (see below), whose sum is σ = 1332282000. Its totient is φ = 220776768.

The previous prime is 664235641. The next prime is 664235651. The reversal of 664235646 is 646532466.

It is an interprime number because it is at equal distance from previous prime (664235641) and next prime (664235651).

It is a junction number, because it is equal to n+sod(n) for n = 664235598 and 664235607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664235641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 156511 + ... + 160698.

It is an arithmetic number, because the mean of its divisors is an integer number (83267625).

Almost surely, 2^664235646 is an apocalyptic number.

664235646 is an abundant number, since it is smaller than the sum of its proper divisors (668046354).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

664235646 is a wasteful number, since it uses less digits than its factorization.

664235646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317563.

The product of its digits is 622080, while the sum is 42.

The square root of 664235646 is about 25772.7694670169. The cubic root of 664235646 is about 872.5173253484.

The spelling of 664235646 in words is "six hundred sixty-four million, two hundred thirty-five thousand, six hundred forty-six".