121756363657121 has 2 divisors, whose sum is σ = 121756363657122. Its totient is φ = 121756363657120.

The previous prime is 121756363657081. The next prime is 121756363657153.

121756363657121 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120308760046225 + 1447603610896 = 10968535^2 + 1203164^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 121756363657121 - 2¹⁰ = 121756363656097 is a prime.

It is a super-2 number, since 2×121756363657121² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121756363657321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60878181828560 + 60878181828561.

It is an arithmetic number, because the mean of its divisors is an integer number (60878181828561).

Almost surely, 2^{121756363657121} is an apocalyptic number.

It is an amenable number.

121756363657121 is a deficient number, since it is larger than the sum of its proper divisors (1).

121756363657121 is an equidigital number, since it uses as much as digits as its factorization.

121756363657121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9525600, while the sum is 56.

The spelling of 121756363657121 in words is "one hundred twenty-one trillion, seven hundred fifty-six billion, three hundred sixty-three million, six hundred fifty-seven thousand, one hundred twenty-one".