64690513920 has 480 divisors, whose sum is σ = 242023541760. Its totient is φ = 16495902720.

The previous prime is 64690513919. The next prime is 64690513931. The reversal of 64690513920 is 2931509646.

64690513920 is a `hidden beast` number, since 6 + 46 + 9 + 0 + 513 + 92 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 39 ways as a sum of consecutive naturals, for example, 19075425 + ... + 19078815.

It is an arithmetic number, because the mean of its divisors is an integer number (504215712).

Almost surely, 2^64690513920 is an apocalyptic number.

64690513920 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 64690513920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121011770880).

64690513920 is an abundant number, since it is smaller than the sum of its proper divisors (177333027840).

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

64690513920 is a wasteful number, since it uses less digits than its factorization.

64690513920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3453 (or 3424 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The spelling of 64690513920 in words is "sixty-four billion, six hundred ninety million, five hundred thirteen thousand, nine hundred twenty".