121309857997 has 2 divisors, whose sum is σ = 121309857998. Its totient is φ = 121309857996.

The previous prime is 121309857953. The next prime is 121309858009. The reversal of 121309857997 is 799758903121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 106706102281 + 14603755716 = 326659^2 + 120846^2 .

It is a cyclic number.

It is not a de Polignac number, because 121309857997 - 2¹⁵ = 121309825229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121309857937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60654928998 + 60654928999.

It is an arithmetic number, because the mean of its divisors is an integer number (60654928999).

Almost surely, 2^121309857997 is an apocalyptic number.

It is an amenable number.

121309857997 is a deficient number, since it is larger than the sum of its proper divisors (1).

121309857997 is an equidigital number, since it uses as much as digits as its factorization.

121309857997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8573040, while the sum is 61.

The spelling of 121309857997 in words is "one hundred twenty-one billion, three hundred nine million, eight hundred fifty-seven thousand, nine hundred ninety-seven".