664394423 has 12 divisors (see below), whose sum is σ = 834612240. Its totient is φ = 517709280.

The previous prime is 664394417. The next prime is 664394429. The reversal of 664394423 is 324493466.

It is an interprime number because it is at equal distance from previous prime (664394417) and next prime (664394429).

It is not a de Polignac number, because 664394423 - 2²⁴ = 647617207 is a prime.

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (664394429) 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 11 ways as a sum of consecutive naturals, for example, 391358 + ... + 393051.

It is an arithmetic number, because the mean of its divisors is an integer number (69551020).

Almost surely, 2^664394423 is an apocalyptic number.

664394423 is a deficient number, since it is larger than the sum of its proper divisors (170217817).

664394423 is a wasteful number, since it uses less digits than its factorization.

664394423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 784438 (or 784427 counting only the distinct ones).

The product of its digits is 373248, while the sum is 41.

The square root of 664394423 is about 25775.8496077239. The cubic root of 664394423 is about 872.5868411632.

The spelling of 664394423 in words is "six hundred sixty-four million, three hundred ninety-four thousand, four hundred twenty-three".