64139217 has 16 divisors (see below), whose sum is σ = 88535040. Its totient is φ = 41259600.

The previous prime is 64139209. The next prime is 64139219. The reversal of 64139217 is 71293146.

It is not a de Polignac number, because 64139217 - 2³ = 64139209 is a prime.

It is a super-2 number, since 2×64139217² = 8227678314746178, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64139219) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 40042 + ... + 41612.

It is an arithmetic number, because the mean of its divisors is an integer number (5533440).

Almost surely, 2^64139217 is an apocalyptic number.

It is an amenable number.

64139217 is a deficient number, since it is larger than the sum of its proper divisors (24395823).

64139217 is a wasteful number, since it uses less digits than its factorization.

64139217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2044.

The product of its digits is 9072, while the sum is 33.

The square root of 64139217 is about 8008.6963358589. The cubic root of 64139217 is about 400.2898253691.

The spelling of 64139217 in words is "sixty-four million, one hundred thirty-nine thousand, two hundred seventeen".