64040391 has 12 divisors (see below), whose sum is σ = 92874600. Its totient is φ = 42522000.

The previous prime is 64040359. The next prime is 64040477. The reversal of 64040391 is 19304046.

It is not a de Polignac number, because 64040391 - 2⁵ = 64040359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64040341) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11916 + ... + 16433.

It is an arithmetic number, because the mean of its divisors is an integer number (7739550).

Almost surely, 2^64040391 is an apocalyptic number.

64040391 is a deficient number, since it is larger than the sum of its proper divisors (28834209).

64040391 is a wasteful number, since it uses less digits than its factorization.

64040391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28606 (or 28603 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 64040391 is about 8002.5240393266. The cubic root of 64040391 is about 400.0841302207.

The spelling of 64040391 in words is "sixty-four million, forty thousand, three hundred ninety-one".