131921121 has 4 divisors (see below), whose sum is σ = 175894832. Its totient is φ = 87947412.

The previous prime is 131921117. The next prime is 131921137. The reversal of 131921121 is 121129131.

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 not a de Polignac number, because 131921121 - 2² = 131921117 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131921221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21986851 + ... + 21986856.

It is an arithmetic number, because the mean of its divisors is an integer number (43973708).

Almost surely, 2^131921121 is an apocalyptic number.

It is an amenable number.

131921121 is a deficient number, since it is larger than the sum of its proper divisors (43973711).

131921121 is an equidigital number, since it uses as much as digits as its factorization.

131921121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43973710.

The product of its digits is 108, while the sum is 21.

The square root of 131921121 is about 11485.6920122385. The cubic root of 131921121 is about 509.0628966217.

The spelling of 131921121 in words is "one hundred thirty-one million, nine hundred twenty-one thousand, one hundred twenty-one".