7856661563520 has 1024 divisors, whose sum is σ = 33525583257600. Its totient is φ = 1514844979200.

The previous prime is 7856661563501. The next prime is 7856661563549. The reversal of 7856661563520 is 253651666587.

It is a Harshad number since it is a multiple of its sum of digits (60).

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, 178420866 + ... + 178464894.

It is an arithmetic number, because the mean of its divisors is an integer number (32739827400).

Almost surely, 2^{7856661563520} is an apocalyptic number.

7856661563520 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 7856661563520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16762791628800).

7856661563520 is an abundant number, since it is smaller than the sum of its proper divisors (25668921694080).

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

7856661563520 is a wasteful number, since it uses less digits than its factorization.

7856661563520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44157 (or 44145 counting only the distinct ones).

The product of its (nonzero) digits is 54432000, while the sum is 60.

The spelling of 7856661563520 in words is "seven trillion, eight hundred fifty-six billion, six hundred sixty-one million, five hundred sixty-three thousand, five hundred twenty".