64689901920 has 864 divisors, whose sum is σ = 274428816480. Its totient is φ = 13795246080.

The previous prime is 64689901907. The next prime is 64689901949. The reversal of 64689901920 is 2910998646.

64689901920 is a `hidden beast` number, since 6 + 468 + 9 + 90 + 1 + 92 + 0 = 666.

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 143 ways as a sum of consecutive naturals, for example, 97866390 + ... + 97867050.

It is an arithmetic number, because the mean of its divisors is an integer number (317625945).

Almost surely, 2^64689901920 is an apocalyptic number.

64689901920 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 64689901920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137214408240).

64689901920 is an abundant number, since it is smaller than the sum of its proper divisors (209738914560).

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

64689901920 is a wasteful number, since it uses less digits than its factorization.

64689901920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788 (or 770 counting only the distinct ones).

The product of its (nonzero) digits is 1679616, while the sum is 54.

The spelling of 64689901920 in words is "sixty-four billion, six hundred eighty-nine million, nine hundred one thousand, nine hundred twenty".