122256657721 has 6 divisors (see below), whose sum is σ = 134381285066. Its totient is φ = 111142416000.

The previous prime is 122256657709. The next prime is 122256657737. The reversal of 122256657721 is 127756652221.

It can be written as a sum of positive squares in only one way, i.e., 111676272400 + 10580385321 = 334180^2 + 102861^2 .

It is not a de Polignac number, because 122256657721 - 2¹⁷ = 122256526649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (122256657221) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 505192680 + ... + 505192921.

Almost surely, 2^122256657721 is an apocalyptic number.

122256657721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

122256657721 is a deficient number, since it is larger than the sum of its proper divisors (12124627345).

122256657721 is a wasteful number, since it uses less digits than its factorization.

122256657721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010385623 (or 1010385612 counting only the distinct ones).

The product of its digits is 705600, while the sum is 46.

It can be divided in two parts, 122256 and 657721, that added together give a palindrome (779977).

The spelling of 122256657721 in words is "one hundred twenty-two billion, two hundred fifty-six million, six hundred fifty-seven thousand, seven hundred twenty-one".