7977177678564 has 120 divisors (see below), whose sum is σ = 21257953045560. Its totient is φ = 2607591108096.

The previous prime is 7977177678559. The next prime is 7977177678637. The reversal of 7977177678564 is 4658767717797.

It can be written as a sum of positive squares in 4 ways, for example, as 5001449177664 + 2975728500900 = 2236392^2 + 1725030^2 .

It is a Harshad number since it is a multiple of its sum of digits (81).

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 34727512 + ... + 34956464.

It is an arithmetic number, because the mean of its divisors is an integer number (177149608713).

Almost surely, 2^{7977177678564} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7977177678564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10628976522780).

7977177678564 is an abundant number, since it is smaller than the sum of its proper divisors (13280775366996).

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

7977177678564 is a wasteful number, since it uses less digits than its factorization.

7977177678564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 231051 (or 231040 counting only the distinct ones).

The product of its digits is 6098924160, while the sum is 81.

The spelling of 7977177678564 in words is "seven trillion, nine hundred seventy-seven billion, one hundred seventy-seven million, six hundred seventy-eight thousand, five hundred sixty-four".