131221316 has 12 divisors (see below), whose sum is σ = 229852140. Its totient is φ = 65549280.

The previous prime is 131221313. The next prime is 131221327. The reversal of 131221316 is 613122131.

It can be written as a sum of positive squares in 2 ways, for example, as 39942400 + 91278916 = 6320^2 + 9554^2 .

It is not an unprimeable number, because it can be changed into a prime (131221313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10355 + ... + 19226.

It is an arithmetic number, because the mean of its divisors is an integer number (19154345).

Almost surely, 2^131221316 is an apocalyptic number.

It is an amenable number.

131221316 is a deficient number, since it is larger than the sum of its proper divisors (98630824).

131221316 is a wasteful number, since it uses less digits than its factorization.

131221316 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30694 (or 30692 counting only the distinct ones).

The product of its digits is 216, while the sum is 20.

The square root of 131221316 is about 11455.1872965919. The cubic root of 131221316 is about 508.1611543602.

Adding to 131221316 its reverse (613122131), we get a palindrome (744343447).

The spelling of 131221316 in words is "one hundred thirty-one million, two hundred twenty-one thousand, three hundred sixteen".