7977786520 has 96 divisors (see below), whose sum is σ = 20891001600. Its totient is φ = 2730337280.

The previous prime is 7977786511. The next prime is 7977786527. The reversal of 7977786520 is 256877797.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7977786527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 33801 + ... + 130759.

It is an arithmetic number, because the mean of its divisors is an integer number (217614600).

Almost surely, 2^7977786520 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 7977786520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10445500800).

7977786520 is an abundant number, since it is smaller than the sum of its proper divisors (12913215080).

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

7977786520 is a wasteful number, since it uses less digits than its factorization.

7977786520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97009 (or 96994 counting only the distinct ones).

The product of its (nonzero) digits is 10372320, while the sum is 58.

The square root of 7977786520 is about 89318.4556516737. The cubic root of 7977786520 is about 1998.1471606900.

It can be divided in two parts, 7977 and 786520, that added together give a palindrome (794497).

The spelling of 7977786520 in words is "seven billion, nine hundred seventy-seven million, seven hundred eighty-six thousand, five hundred twenty".