64813691 has 4 divisors (see below), whose sum is σ = 65308584. Its totient is φ = 64318800.

The previous prime is 64813663. The next prime is 64813711. The reversal of 64813691 is 19631846.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 64813691 - 2²² = 60619387 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64813631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 247250 + ... + 247511.

It is an arithmetic number, because the mean of its divisors is an integer number (16327146).

Almost surely, 2^64813691 is an apocalyptic number.

64813691 is a deficient number, since it is larger than the sum of its proper divisors (494893).

64813691 is a wasteful number, since it uses less digits than its factorization.

64813691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 494892.

The product of its digits is 31104, while the sum is 38.

The square root of 64813691 is about 8050.6950631607. The cubic root of 64813691 is about 401.6880557318.

The spelling of 64813691 in words is "sixty-four million, eight hundred thirteen thousand, six hundred ninety-one".