64386691 has 4 divisors (see below), whose sum is σ = 64525032. Its totient is φ = 64248352.

The previous prime is 64386671. The next prime is 64386703. The reversal of 64386691 is 19668346.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19668346 = 2 ⋅9834173.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64386691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64386601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68470 + ... + 69403.

It is an arithmetic number, because the mean of its divisors is an integer number (16131258).

Almost surely, 2^64386691 is an apocalyptic number.

64386691 is a deficient number, since it is larger than the sum of its proper divisors (138341).

64386691 is a wasteful number, since it uses less digits than its factorization.

64386691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138340.

The product of its digits is 186624, while the sum is 43.

The square root of 64386691 is about 8024.1317910413. The cubic root of 64386691 is about 400.8039891708.

The spelling of 64386691 in words is "sixty-four million, three hundred eighty-six thousand, six hundred ninety-one".