7961581393920 has 2496 divisors, whose sum is σ = 37605591878400. Its totient is φ = 1567283281920.

The previous prime is 7961581393841. The next prime is 7961581393937. The reversal of 7961581393920 is 293931851697.

7961581393920 is a `hidden beast` number, since 7 + 9 + 6 + 158 + 1 + 393 + 92 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 207 ways as a sum of consecutive naturals, for example, 419030599671 + ... + 419030599689.

It is an arithmetic number, because the mean of its divisors is an integer number (15066342900).

Almost surely, 2^{7961581393920} is an apocalyptic number.

7961581393920 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 7961581393920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18802795939200).

7961581393920 is an abundant number, since it is smaller than the sum of its proper divisors (29644010484480).

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

7961581393920 is an frugal number, since it uses more digits than its factorization.

7961581393920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100 (or 47 counting only the distinct ones).

The product of its (nonzero) digits is 22044960, while the sum is 63.

The spelling of 7961581393920 in words is "seven trillion, nine hundred sixty-one billion, five hundred eighty-one million, three hundred ninety-three thousand, nine hundred twenty".