131211121 has 4 divisors (see below), whose sum is σ = 131240692. Its totient is φ = 131181552.

The previous prime is 131211097. The next prime is 131211133. The reversal of 131211121 is 121112131.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 66585600 + 64625521 = 8160^2 + 8039^2 .

It is a cyclic number.

It is not a de Polignac number, because 131211121 - 2⁵ = 131211089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131211181) 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, 6630 + ... + 17503.

It is an arithmetic number, because the mean of its divisors is an integer number (32810173).

Almost surely, 2^131211121 is an apocalyptic number.

It is an amenable number.

131211121 is a deficient number, since it is larger than the sum of its proper divisors (29571).

131211121 is an equidigital number, since it uses as much as digits as its factorization.

131211121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29570.

The product of its digits is 12, while the sum is 13.

The square root of 131211121 is about 11454.7422930418. The cubic root of 131211121 is about 508.1479938024.

Adding to 131211121 its reverse (121112131), we get a palindrome (252323252).

The spelling of 131211121 in words is "one hundred thirty-one million, two hundred eleven thousand, one hundred twenty-one".