131221022121 has 24 divisors (see below), whose sum is σ = 216719295104. Its totient is φ = 74948664960.

The previous prime is 131221022083. The next prime is 131221022137. The reversal of 131221022121 is 121220122131.

131221022121 is a `hidden beast` number, since 1 + 312 + 210 + 22 + 121 = 666.

It is not a de Polignac number, because 131221022121 - 2⁹ = 131221021609 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 131221022094 and 131221022103.

It is not an unprimeable number, because it can be changed into a prime (131221022161) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 345781 + ... + 618066.

Almost surely, 2^131221022121 is an apocalyptic number.

It is an amenable number.

131221022121 is a deficient number, since it is larger than the sum of its proper divisors (85498272983).

131221022121 is a wasteful number, since it uses less digits than its factorization.

131221022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 966021 (or 966018 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 18.

Adding to 131221022121 its reverse (121220122131), we get a palindrome (252441144252).

It can be divided in two parts, 1312210 and 22121, that added together give a palindrome (1334331).

The spelling of 131221022121 in words is "one hundred thirty-one billion, two hundred twenty-one million, twenty-two thousand, one hundred twenty-one".