64865520 has 120 divisors (see below), whose sum is σ = 227369376. Its totient is φ = 16541184.

The previous prime is 64865501. The next prime is 64865561. The reversal of 64865520 is 2556846.

64865520 is a `hidden beast` number, since 648 + 6 + 5 + 5 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 14602 + ... + 18518.

Almost surely, 2^64865520 is an apocalyptic number.

64865520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 64865520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113684688).

64865520 is an abundant number, since it is smaller than the sum of its proper divisors (162503856).

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

64865520 is a wasteful number, since it uses less digits than its factorization.

64865520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3959 (or 3950 counting only the distinct ones).

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

The square root of 64865520 is about 8053.9133345225. The cubic root of 64865520 is about 401.7950986676.

The spelling of 64865520 in words is "sixty-four million, eight hundred sixty-five thousand, five hundred twenty".