64685520 has 80 divisors (see below), whose sum is σ = 222813120. Its totient is φ = 17248896.

The previous prime is 64685513. The next prime is 64685521. The reversal of 64685520 is 2558646.

64685520 is a `hidden beast` number, since 646 + 8 + 5 + 5 + 2 + 0 = 666.

64685520 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64685521) by changing a digit.

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, 12814 + ... + 17133.

It is an arithmetic number, because the mean of its divisors is an integer number (2785164).

Almost surely, 2^64685520 is an apocalyptic number.

64685520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64685520 is an abundant number, since it is smaller than the sum of its proper divisors (158127600).

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

64685520 is a wasteful number, since it uses less digits than its factorization.

64685520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29969 (or 29957 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 64685520 is about 8042.7308794961. The cubic root of 64685520 is about 401.4230976451.

It can be divided in two parts, 64 and 685520, that added together give a square (685584 = 828²).

The spelling of 64685520 in words is "sixty-four million, six hundred eighty-five thousand, five hundred twenty".