131221440309 has 4 divisors (see below), whose sum is σ = 174961920416. Its totient is φ = 87480960204.

The previous prime is 131221440277. The next prime is 131221440323. The reversal of 131221440309 is 903044122131.

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 131221440309 - 2⁵ = 131221440277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131221440509) 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, 21870240049 + ... + 21870240054.

It is an arithmetic number, because the mean of its divisors is an integer number (43740480104).

Almost surely, 2^131221440309 is an apocalyptic number.

It is an amenable number.

131221440309 is a deficient number, since it is larger than the sum of its proper divisors (43740480107).

131221440309 is an equidigital number, since it uses as much as digits as its factorization.

131221440309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43740480106.

The product of its (nonzero) digits is 5184, while the sum is 30.

The spelling of 131221440309 in words is "one hundred thirty-one billion, two hundred twenty-one million, four hundred forty thousand, three hundred nine".