121605127657 has 16 divisors (see below), whose sum is σ = 132515724880. Its totient is φ = 110922400512.

The previous prime is 121605127619. The next prime is 121605127669. The reversal of 121605127657 is 756721506121.

It can be written as a sum of positive squares in 8 ways, for example, as 13472012761 + 108133114896 = 116069^2 + 328836^2 .

It is a cyclic number.

It is not a de Polignac number, because 121605127657 - 2⁷ = 121605127529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121605127607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 413503 + ... + 643579.

It is an arithmetic number, because the mean of its divisors is an integer number (8282232805).

Almost surely, 2^121605127657 is an apocalyptic number.

It is an amenable number.

121605127657 is a deficient number, since it is larger than the sum of its proper divisors (10910597223).

121605127657 is a wasteful number, since it uses less digits than its factorization.

121605127657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230572.

The product of its (nonzero) digits is 176400, while the sum is 43.

The spelling of 121605127657 in words is "one hundred twenty-one billion, six hundred five million, one hundred twenty-seven thousand, six hundred fifty-seven".