64563391 has 2 divisors, whose sum is σ = 64563392. Its totient is φ = 64563390.

The previous prime is 64563377. The next prime is 64563413. The reversal of 64563391 is 19336546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64563391 - 2¹³ = 64555199 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 64563391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64564391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32281695 + 32281696.

It is an arithmetic number, because the mean of its divisors is an integer number (32281696).

Almost surely, 2^64563391 is an apocalyptic number.

64563391 is a deficient number, since it is larger than the sum of its proper divisors (1).

64563391 is an equidigital number, since it uses as much as digits as its factorization.

64563391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 37.

The square root of 64563391 is about 8035.1347841838. The cubic root of 64563391 is about 401.1703038828.

The spelling of 64563391 in words is "sixty-four million, five hundred sixty-three thousand, three hundred ninety-one".