7947904981 has 12 divisors (see below), whose sum is σ = 8432224164. Its totient is φ = 7486640000.

The previous prime is 7947904969. The next prime is 7947905011. The reversal of 7947904981 is 1894097497.

It can be written as a sum of positive squares in 6 ways, for example, as 402203025 + 7545701956 = 20055^2 + 86866^2 .

It is not a de Polignac number, because 7947904981 - 2²⁷ = 7813687253 is a prime.

It is a super-2 number, since 2×7947904981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7947902981) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 80770 + ... + 149731.

It is an arithmetic number, because the mean of its divisors is an integer number (702685347).

Almost surely, 2^7947904981 is an apocalyptic number.

It is an amenable number.

7947904981 is a deficient number, since it is larger than the sum of its proper divisors (484319183).

7947904981 is a wasteful number, since it uses less digits than its factorization.

7947904981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230600 (or 230571 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 58.

The square root of 7947904981 is about 89151.0234433683. The cubic root of 7947904981 is about 1995.6492909448.

The spelling of 7947904981 in words is "seven billion, nine hundred forty-seven million, nine hundred four thousand, nine hundred eighty-one".