64640923 has 2 divisors, whose sum is σ = 64640924. Its totient is φ = 64640922.

The previous prime is 64640861. The next prime is 64640941. The reversal of 64640923 is 32904646.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64640923 is a prime.

It is not a weakly prime, because it can be changed into another prime (64640963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32320461 + 32320462.

It is an arithmetic number, because the mean of its divisors is an integer number (32320462).

Almost surely, 2^64640923 is an apocalyptic number.

64640923 is a deficient number, since it is larger than the sum of its proper divisors (1).

64640923 is an equidigital number, since it uses as much as digits as its factorization.

64640923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 34.

The square root of 64640923 is about 8039.9578978997. The cubic root of 64640923 is about 401.3308236109.

The spelling of 64640923 in words is "sixty-four million, six hundred forty thousand, nine hundred twenty-three".