64515720 has 64 divisors (see below), whose sum is σ = 200232000. Its totient is φ = 16610048.

The previous prime is 64515719. The next prime is 64515751. The reversal of 64515720 is 2751546.

64515720 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5790 + ... + 12749.

It is an arithmetic number, because the mean of its divisors is an integer number (3128625).

Almost surely, 2^64515720 is an apocalyptic number.

64515720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64515720 is an abundant number, since it is smaller than the sum of its proper divisors (135716280).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64515720 is a wasteful number, since it uses less digits than its factorization.

64515720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18582 (or 18578 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 64515720 is about 8032.1678269319. The cubic root of 64515720 is about 401.0715435893.

The spelling of 64515720 in words is "sixty-four million, five hundred fifteen thousand, seven hundred twenty".