64641515 has 16 divisors (see below), whose sum is σ = 82473120. Its totient is φ = 48499200.

The previous prime is 64641509. The next prime is 64641539. The reversal of 64641515 is 51514646.

It is not a de Polignac number, because 64641515 - 2²⁰ = 63592939 is a prime.

It is a super-2 number, since 2×64641515² = 8357050922990450, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6227 + ... + 12963.

It is an arithmetic number, because the mean of its divisors is an integer number (5154570).

Almost surely, 2^64641515 is an apocalyptic number.

64641515 is a deficient number, since it is larger than the sum of its proper divisors (17831605).

64641515 is a wasteful number, since it uses less digits than its factorization.

64641515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6862.

The product of its digits is 14400, while the sum is 32.

The square root of 64641515 is about 8039.9947139286. The cubic root of 64641515 is about 401.3320487745.

It can be divided in two parts, 64641 and 515, that added together give a palindrome (65156).

The spelling of 64641515 in words is "sixty-four million, six hundred forty-one thousand, five hundred fifteen".