63964736640 has 512 divisors, whose sum is σ = 263179584000. Its totient is φ = 14379171840.

The previous prime is 63964736629. The next prime is 63964736651. The reversal of 63964736640 is 4663746936.

It is an interprime number because it is at equal distance from previous prime (63964736629) and next prime (63964736651).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 7374226 + ... + 7382894.

It is an arithmetic number, because the mean of its divisors is an integer number (514022625).

Almost surely, 2^63964736640 is an apocalyptic number.

63964736640 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 63964736640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131589792000).

63964736640 is an abundant number, since it is smaller than the sum of its proper divisors (199214847360).

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

63964736640 is a wasteful number, since it uses less digits than its factorization.

63964736640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8765 (or 8747 counting only the distinct ones).

The product of its (nonzero) digits is 11757312, while the sum is 54.

The spelling of 63964736640 in words is "sixty-three billion, nine hundred sixty-four million, seven hundred thirty-six thousand, six hundred forty".