7977808681920 has 2688 divisors, whose sum is σ = 36850700390400. Its totient is φ = 1567321620480.

The previous prime is 7977808681879. The next prime is 7977808681961. The reversal of 7977808681920 is 291868087797.

It is an interprime number because it is at equal distance from previous prime (7977808681879) and next prime (7977808681961).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 34239522124 + ... + 34239522356.

Almost surely, 2^{7977808681920} is an apocalyptic number.

7977808681920 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 7977808681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18425350195200).

7977808681920 is an abundant number, since it is smaller than the sum of its proper divisors (28872891708480).

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

7977808681920 is a wasteful number, since it uses less digits than its factorization.

7977808681920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448 (or 421 counting only the distinct ones).

The product of its (nonzero) digits is 170698752, while the sum is 72.

The spelling of 7977808681920 in words is "seven trillion, nine hundred seventy-seven billion, eight hundred eight million, six hundred eighty-one thousand, nine hundred twenty".