64635691 has 2 divisors, whose sum is σ = 64635692. Its totient is φ = 64635690.

The previous prime is 64635689. The next prime is 64635719. The reversal of 64635691 is 19653646.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 64635691 - 2¹ = 64635689 is a prime.

It is a super-3 number, since 3×64635691³ (a number of 24 digits) contains 333 as substring.

Together with 64635689, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (64635601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32317845 + 32317846.

It is an arithmetic number, because the mean of its divisors is an integer number (32317846).

Almost surely, 2^64635691 is an apocalyptic number.

64635691 is a deficient number, since it is larger than the sum of its proper divisors (1).

64635691 is an equidigital number, since it uses as much as digits as its factorization.

64635691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 40.

The square root of 64635691 is about 8039.6325164774. The cubic root of 64635691 is about 401.3199954882.

The spelling of 64635691 in words is "sixty-four million, six hundred thirty-five thousand, six hundred ninety-one".