79775681 has 2 divisors, whose sum is σ = 79775682. Its totient is φ = 79775680.

The previous prime is 79775677. The next prime is 79775693. The reversal of 79775681 is 18657797.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46240000 + 33535681 = 6800^2 + 5791^2 .

It is an emirp because it is prime and its reverse (18657797) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79775681 - 2² = 79775677 is a prime.

It is a super-2 number, since 2×79775681² = 12728318558027522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (79775981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39887840 + 39887841.

It is an arithmetic number, because the mean of its divisors is an integer number (39887841).

Almost surely, 2^79775681 is an apocalyptic number.

It is an amenable number.

79775681 is a deficient number, since it is larger than the sum of its proper divisors (1).

79775681 is an equidigital number, since it uses as much as digits as its factorization.

79775681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 740880, while the sum is 50.

The square root of 79775681 is about 8931.7232939674. The cubic root of 79775681 is about 430.4838271360.

The spelling of 79775681 in words is "seventy-nine million, seven hundred seventy-five thousand, six hundred eighty-one".