97936861375721 has 2 divisors, whose sum is σ = 97936861375722. Its totient is φ = 97936861375720.

The previous prime is 97936861375637. The next prime is 97936861375739. The reversal of 97936861375721 is 12757316863979.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87049105260121 + 10887756115600 = 9330011^2 + 3299660^2 .

It is a cyclic number.

It is not a de Polignac number, because 97936861375721 - 2¹⁸ = 97936861113577 is a prime.

It is a super-2 number, since 2×97936861375721² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (97936861375741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48968430687860 + 48968430687861.

It is an arithmetic number, because the mean of its divisors is an integer number (48968430687861).

Almost surely, 2^{97936861375721} is an apocalyptic number.

It is an amenable number.

97936861375721 is a deficient number, since it is larger than the sum of its proper divisors (1).

97936861375721 is an equidigital number, since it uses as much as digits as its factorization.

97936861375721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 720135360, while the sum is 74.

The spelling of 97936861375721 in words is "ninety-seven trillion, nine hundred thirty-six billion, eight hundred sixty-one million, three hundred seventy-five thousand, seven hundred twenty-one".