131221100121 has 4 divisors (see below), whose sum is σ = 174961466832. Its totient is φ = 87480733412.

The previous prime is 131221100111. The next prime is 131221100149. The reversal of 131221100121 is 121001122131.

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.

It is a cyclic number.

It is not a de Polignac number, because 131221100121 - 2¹⁸ = 131220837977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131221100121.

It is not an unprimeable number, because it can be changed into a prime (131221100111) 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, 21870183351 + ... + 21870183356.

It is an arithmetic number, because the mean of its divisors is an integer number (43740366708).

Almost surely, 2^131221100121 is an apocalyptic number.

It is an amenable number.

131221100121 is a deficient number, since it is larger than the sum of its proper divisors (43740366711).

131221100121 is an equidigital number, since it uses as much as digits as its factorization.

131221100121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43740366710.

The product of its (nonzero) digits is 24, while the sum is 15.

Adding to 131221100121 its reverse (121001122131), we get a palindrome (252222222252).

The spelling of 131221100121 in words is "one hundred thirty-one billion, two hundred twenty-one million, one hundred thousand, one hundred twenty-one".