64915691 has 2 divisors, whose sum is σ = 64915692. Its totient is φ = 64915690.

The previous prime is 64915687. The next prime is 64915693. The reversal of 64915691 is 19651946.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 64915691 - 2² = 64915687 is a prime.

Together with 64915693, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (64915693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32457845 + 32457846.

It is an arithmetic number, because the mean of its divisors is an integer number (32457846).

Almost surely, 2^64915691 is an apocalyptic number.

64915691 is a deficient number, since it is larger than the sum of its proper divisors (1).

64915691 is an equidigital number, since it uses as much as digits as its factorization.

64915691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58320, while the sum is 41.

The square root of 64915691 is about 8057.0274295177. The cubic root of 64915691 is about 401.8986630207.

The spelling of 64915691 in words is "sixty-four million, nine hundred fifteen thousand, six hundred ninety-one".