7931864640 has 896 divisors, whose sum is σ = 32912547840. Its totient is φ = 1576599552.

The previous prime is 7931864639. The next prime is 7931864651. The reversal of 7931864640 is 464681397.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 7931864640.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 108655644 + ... + 108655716.

Almost surely, 2^7931864640 is an apocalyptic number.

7931864640 is a gapful number since it is divisible by the number (70) 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 7931864640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16456273920).

7931864640 is an abundant number, since it is smaller than the sum of its proper divisors (24980683200).

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

7931864640 is a wasteful number, since it uses less digits than its factorization.

7931864640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 169 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 48.

The square root of 7931864640 is about 89061.0163876429. The cubic root of 7931864640 is about 1994.3058570868.

The spelling of 7931864640 in words is "seven billion, nine hundred thirty-one million, eight hundred sixty-four thousand, six hundred forty".