131312121 has 4 divisors (see below), whose sum is σ = 175082832. Its totient is φ = 87541412.

The previous prime is 131312047. The next prime is 131312147. The reversal of 131312121 is 121213131.

It is a happy number.

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 131312121 - 2¹⁸ = 131049977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 131312121.

It is not an unprimeable number, because it can be changed into a prime (131312521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21885351 + ... + 21885356.

It is an arithmetic number, because the mean of its divisors is an integer number (43770708).

Almost surely, 2^131312121 is an apocalyptic number.

It is an amenable number.

131312121 is a deficient number, since it is larger than the sum of its proper divisors (43770711).

131312121 is an equidigital number, since it uses as much as digits as its factorization.

131312121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43770710.

The product of its digits is 36, while the sum is 15.

The square root of 131312121 is about 11459.1500993747. The cubic root of 131312121 is about 508.2783429780.

Adding to 131312121 its reverse (121213131), we get a palindrome (252525252).

The spelling of 131312121 in words is "one hundred thirty-one million, three hundred twelve thousand, one hundred twenty-one".