79684981 has 2 divisors, whose sum is σ = 79684982. Its totient is φ = 79684980.

The previous prime is 79684919. The next prime is 79685029. The reversal of 79684981 is 18948697.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 60684100 + 19000881 = 7790^2 + 4359^2 .

It is an emirp because it is prime and its reverse (18948697) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 79684981 - 2⁹ = 79684469 is a prime.

It is a super-2 number, since 2×79684981² = 12699392393940722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79684181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39842490 + 39842491.

It is an arithmetic number, because the mean of its divisors is an integer number (39842491).

Almost surely, 2^79684981 is an apocalyptic number.

It is an amenable number.

79684981 is a deficient number, since it is larger than the sum of its proper divisors (1).

79684981 is an equidigital number, since it uses as much as digits as its factorization.

79684981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 870912, while the sum is 52.

The square root of 79684981 is about 8926.6444423423. The cubic root of 79684981 is about 430.3206208005.

The spelling of 79684981 in words is "seventy-nine million, six hundred eighty-four thousand, nine hundred eighty-one".