8900720640 has 864 divisors, whose sum is σ = 37723598640. Its totient is φ = 2006581248.

The previous prime is 8900720623. The next prime is 8900720657. The reversal of 8900720640 is 460270098.

8900720640 is a `hidden beast` number, since 8 + 9 + 0 + 0 + 7 + 2 + 0 + 640 = 666.

It is an interprime number because it is at equal distance from previous prime (8900720623) and next prime (8900720657).

It is a tau number, because it is divible by the number of its divisors (864).

It is a super-2 number, since 2×8900720640² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 8900720595 and 8900720604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 121927644 + ... + 121927716.

Almost surely, 2^8900720640 is an apocalyptic number.

8900720640 is a gapful number since it is divisible by the number (80) 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 8900720640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18861799320).

8900720640 is an abundant number, since it is smaller than the sum of its proper divisors (28822878000).

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

8900720640 is an equidigital number, since it uses as much as digits as its factorization.

8900720640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 90 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 8900720640 is about 94343.6306276158. The cubic root of 8900720640 is about 2072.4070298491.

The spelling of 8900720640 in words is "eight billion, nine hundred million, seven hundred twenty thousand, six hundred forty".