79969618521 has 45 divisors (see below), whose sum is σ = 129410489901. Its totient is φ = 49191712128.

The previous prime is 79969618483. The next prime is 79969618577. The reversal of 79969618521 is 12581696997.

The square root of 79969618521 is 282789.

It is a perfect power (a square), and thus also a powerful number.

79969618521 is a `hidden beast` number, since 7 + 9 + 9 + 6 + 9 + 618 + 5 + 2 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 4223570121 + 75746048400 = 64989^2 + 275220^2 .

It is not a de Polignac number, because 79969618521 - 2²³ = 79961229913 is a prime.

It is not an unprimeable number, because it can be changed into a prime (79969611521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 33085105 + ... + 33087521.

Almost surely, 2^79969618521 is an apocalyptic number.

79969618521 is the 282789-th square number.

79969618521 is the 141395-th centered octagonal number.

It is an amenable number.

79969618521 is a deficient number, since it is larger than the sum of its proper divisors (49440871380).

79969618521 is an frugal number, since it uses more digits than its factorization.

79969618521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4872 (or 2433 counting only the distinct ones).

The product of its digits is 14696640, while the sum is 63.

The spelling of 79969618521 in words is "seventy-nine billion, nine hundred sixty-nine million, six hundred eighteen thousand, five hundred twenty-one".