131221242 has 32 divisors (see below), whose sum is σ = 295963200. Its totient is φ = 43086384.

The previous prime is 131221231. The next prime is 131221247. The reversal of 131221242 is 242122131.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (131221247) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14517 + ... + 21752.

It is an arithmetic number, because the mean of its divisors is an integer number (9248850).

Almost surely, 2^131221242 is an apocalyptic number.

131221242 is an abundant number, since it is smaller than the sum of its proper divisors (164741958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

131221242 is a wasteful number, since it uses less digits than its factorization.

131221242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36347 (or 36341 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 131221242 is about 11455.1840666137. The cubic root of 131221242 is about 508.1610588373.

Adding to 131221242 its reverse (242122131), we get a palindrome (373343373).

The spelling of 131221242 in words is "one hundred thirty-one million, two hundred twenty-one thousand, two hundred forty-two".