121638738650257 has 2 divisors, whose sum is σ = 121638738650258. Its totient is φ = 121638738650256.

The previous prime is 121638738650239. The next prime is 121638738650269. The reversal of 121638738650257 is 752056837836121.

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., 94068583618816 + 27570155031441 = 9698896^2 + 5250729^2 .

It is a cyclic number.

It is not a de Polignac number, because 121638738650257 - 2¹¹ = 121638738648209 is a prime.

It is a super-2 number, since 2×121638738650257² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (121638738650057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60819369325128 + 60819369325129.

It is an arithmetic number, because the mean of its divisors is an integer number (60819369325129).

Almost surely, 2^{121638738650257} is an apocalyptic number.

It is an amenable number.

121638738650257 is a deficient number, since it is larger than the sum of its proper divisors (1).

121638738650257 is an equidigital number, since it uses as much as digits as its factorization.

121638738650257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 101606400, while the sum is 64.

The spelling of 121638738650257 in words is "one hundred twenty-one trillion, six hundred thirty-eight billion, seven hundred thirty-eight million, six hundred fifty thousand, two hundred fifty-seven".