121256657621 has 8 divisors (see below), whose sum is σ = 132301866144. Its totient is φ = 110215095120.

The previous prime is 121256657581. The next prime is 121256657657. The reversal of 121256657621 is 126756652121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 121256657621 - 2¹⁴ = 121256641237 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121256657321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 841730 + ... + 975203.

It is an arithmetic number, because the mean of its divisors is an integer number (16537733268).

Almost surely, 2^121256657621 is an apocalyptic number.

121256657621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121256657621 is a deficient number, since it is larger than the sum of its proper divisors (11045208523).

121256657621 is a wasteful number, since it uses less digits than its factorization.

121256657621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1823011.

The product of its digits is 302400, while the sum is 44.

It can be divided in two parts, 121256 and 657621, that added together give a palindrome (778877).

The spelling of 121256657621 in words is "one hundred twenty-one billion, two hundred fifty-six million, six hundred fifty-seven thousand, six hundred twenty-one".