64402391 has 2 divisors, whose sum is σ = 64402392. Its totient is φ = 64402390.

The previous prime is 64402319. The next prime is 64402399. The reversal of 64402391 is 19320446.

Together with previous prime (64402319) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64402391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64402399) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32201195 + 32201196.

It is an arithmetic number, because the mean of its divisors is an integer number (32201196).

Almost surely, 2^64402391 is an apocalyptic number.

64402391 is a deficient number, since it is larger than the sum of its proper divisors (1).

64402391 is an equidigital number, since it uses as much as digits as its factorization.

64402391 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 64402391 is about 8025.1100303983. The cubic root of 64402391 is about 400.8365637663.

The spelling of 64402391 in words is "sixty-four million, four hundred two thousand, three hundred ninety-one".