64555920 has 480 divisors, whose sum is σ = 277065600. Its totient is φ = 13685760.

The previous prime is 64555913. The next prime is 64555951. The reversal of 64555920 is 2955546.

64555920 is a `hidden beast` number, since 64 + 5 + 5 + 592 + 0 = 666.

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 95 ways as a sum of consecutive naturals, for example, 3397671 + ... + 3397689.

It is an arithmetic number, because the mean of its divisors is an integer number (577220).

Almost surely, 2^64555920 is an apocalyptic number.

64555920 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 64555920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138532800).

64555920 is an abundant number, since it is smaller than the sum of its proper divisors (212509680).

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

64555920 is a wasteful number, since it uses less digits than its factorization.

64555920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76 (or 53 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 64555920 is about 8034.6698749855. The cubic root of 64555920 is about 401.1548293808.

It can be divided in two parts, 645 and 55920, that added together give a palindrome (56565).

The spelling of 64555920 in words is "sixty-four million, five hundred fifty-five thousand, nine hundred twenty".