131221311 has 8 divisors (see below), whose sum is σ = 188420400. Its totient is φ = 80751552.

The previous prime is 131221303. The next prime is 131221313. The reversal of 131221311 is 113122131.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 131221311 - 2³ = 131221303 is a prime.

It is a congruent number.

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 (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1682286 + ... + 1682363.

It is an arithmetic number, because the mean of its divisors is an integer number (23552550).

Almost surely, 2^131221311 is an apocalyptic number.

131221311 is a deficient number, since it is larger than the sum of its proper divisors (57199089).

131221311 is a wasteful number, since it uses less digits than its factorization.

131221311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3364665.

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

The square root of 131221311 is about 11455.1870783501. The cubic root of 131221311 is about 508.1611479059.

Adding to 131221311 its reverse (113122131), we get a palindrome (244343442).

The spelling of 131221311 in words is "one hundred thirty-one million, two hundred twenty-one thousand, three hundred eleven".