121556225657 has 4 divisors (see below), whose sum is σ = 121557072000. Its totient is φ = 121555379316.

The previous prime is 121556225633. The next prime is 121556225669. The reversal of 121556225657 is 756522655121.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 121556225657 - 2¹⁸ = 121555963513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121556225627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 148157 + ... + 514842.

It is an arithmetic number, because the mean of its divisors is an integer number (30389268000).

Almost surely, 2^121556225657 is an apocalyptic number.

It is an amenable number.

121556225657 is a deficient number, since it is larger than the sum of its proper divisors (846343).

121556225657 is an equidigital number, since it uses as much as digits as its factorization.

121556225657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 846342.

The product of its digits is 1260000, while the sum is 47.

The spelling of 121556225657 in words is "one hundred twenty-one billion, five hundred fifty-six million, two hundred twenty-five thousand, six hundred fifty-seven".