20964631680 has 512 divisors, whose sum is σ = 76988620800. Its totient is φ = 5388042240.

The previous prime is 20964631669. The next prime is 20964631759. The reversal of 20964631680 is 8613646902.

20964631680 is a `hidden beast` number, since 2 + 0 + 9 + 6 + 4 + 631 + 6 + 8 + 0 = 666.

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

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, 89976844 + ... + 89977076.

It is an arithmetic number, because the mean of its divisors is an integer number (150368400).

Almost surely, 2^20964631680 is an apocalyptic number.

20964631680 is a gapful number since it is divisible by the number (20) 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 20964631680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38494310400).

20964631680 is an abundant number, since it is smaller than the sum of its proper divisors (56023989120).

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

20964631680 is a wasteful number, since it uses less digits than its factorization.

20964631680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429 (or 411 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 20964631680 in words is "twenty billion, nine hundred sixty-four million, six hundred thirty-one thousand, six hundred eighty".