79819953121 has 2 divisors, whose sum is σ = 79819953122. Its totient is φ = 79819953120.

The previous prime is 79819953053. The next prime is 79819953131. The reversal of 79819953121 is 12135991897.

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., 62120577600 + 17699375521 = 249240^2 + 133039^2 .

It is a cyclic number.

It is not a de Polignac number, because 79819953121 - 2⁹ = 79819952609 is a prime.

It is not a weakly prime, because it can be changed into another prime (79819953131) 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 as a sum of consecutive naturals, namely, 39909976560 + 39909976561.

It is an arithmetic number, because the mean of its divisors is an integer number (39909976561).

Almost surely, 2^79819953121 is an apocalyptic number.

It is an amenable number.

79819953121 is a deficient number, since it is larger than the sum of its proper divisors (1).

79819953121 is an equidigital number, since it uses as much as digits as its factorization.

79819953121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1224720, while the sum is 55.

The spelling of 79819953121 in words is "seventy-nine billion, eight hundred nineteen million, nine hundred fifty-three thousand, one hundred twenty-one".