7977921582 has 16 divisors (see below), whose sum is σ = 15966283392. Its totient is φ = 2657567160.

The previous prime is 7977921577. The next prime is 7977921587. The reversal of 7977921582 is 2851297797.

It is an interprime number because it is at equal distance from previous prime (7977921577) and next prime (7977921587).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7977921587) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 425058 + ... + 443429.

It is an arithmetic number, because the mean of its divisors is an integer number (997892712).

Almost surely, 2^7977921582 is an apocalyptic number.

7977921582 is an abundant number, since it is smaller than the sum of its proper divisors (7988361810).

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

7977921582 is a wasteful number, since it uses less digits than its factorization.

7977921582 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 870023.

The product of its digits is 4445280, while the sum is 57.

The square root of 7977921582 is about 89319.2117184204. The cubic root of 7977921582 is about 1998.1584366760.

The spelling of 7977921582 in words is "seven billion, nine hundred seventy-seven million, nine hundred twenty-one thousand, five hundred eighty-two".