64920491 has 2 divisors, whose sum is σ = 64920492. Its totient is φ = 64920490.

The previous prime is 64920463. The next prime is 64920523. The reversal of 64920491 is 19402946.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64920491 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (64923491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32460245 + 32460246.

It is an arithmetic number, because the mean of its divisors is an integer number (32460246).

Almost surely, 2^64920491 is an apocalyptic number.

64920491 is a deficient number, since it is larger than the sum of its proper divisors (1).

64920491 is an equidigital number, since it uses as much as digits as its factorization.

64920491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15552, while the sum is 35.

The square root of 64920491 is about 8057.3253006193. The cubic root of 64920491 is about 401.9085685151.

The spelling of 64920491 in words is "sixty-four million, nine hundred twenty thousand, four hundred ninety-one".