64566377478391 has 2 divisors, whose sum is σ = 64566377478392. Its totient is φ = 64566377478390.

The previous prime is 64566377478359. The next prime is 64566377478403. The reversal of 64566377478391 is 19387477366546.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64566377478391 - 2⁵ = 64566377478359 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (64566377478301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32283188739195 + 32283188739196.

It is an arithmetic number, because the mean of its divisors is an integer number (32283188739196).

Almost surely, 2^{64566377478391} is an apocalyptic number.

64566377478391 is a deficient number, since it is larger than the sum of its proper divisors (1).

64566377478391 is an equidigital number, since it uses as much as digits as its factorization.

64566377478391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3840721920, while the sum is 76.

The spelling of 64566377478391 in words is "sixty-four trillion, five hundred sixty-six billion, three hundred seventy-seven million, four hundred seventy-eight thousand, three hundred ninety-one".