79721308685069 has 2 divisors, whose sum is σ = 79721308685070. Its totient is φ = 79721308685068.

The previous prime is 79721308685023. The next prime is 79721308685089. The reversal of 79721308685069 is 96058680312797.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 71930583816100 + 7790724868969 = 8481190^2 + 2791187^2 .

It is a cyclic number.

It is not a de Polignac number, because 79721308685069 - 2¹² = 79721308680973 is a prime.

It is a super-2 number, since 2×79721308685069² (a number of 29 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 79721308684993 and 79721308685011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (79721308685089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39860654342534 + 39860654342535.

It is an arithmetic number, because the mean of its divisors is an integer number (39860654342535).

Almost surely, 2^{79721308685069} is an apocalyptic number.

It is an amenable number.

79721308685069 is a deficient number, since it is larger than the sum of its proper divisors (1).

79721308685069 is an equidigital number, since it uses as much as digits as its factorization.

79721308685069 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 274337280, while the sum is 71.

The spelling of 79721308685069 in words is "seventy-nine trillion, seven hundred twenty-one billion, three hundred eight million, six hundred eighty-five thousand, sixty-nine".