131221441 has 4 divisors (see below), whose sum is σ = 141315412. Its totient is φ = 121127472.

The previous prime is 131221439. The next prime is 131221457. The reversal of 131221441 is 144122131.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 36723600 + 94497841 = 6060^2 + 9721^2 .

It is a cyclic number.

It is not a de Polignac number, because 131221441 - 2¹ = 131221439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131221411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5046966 + ... + 5046991.

It is an arithmetic number, because the mean of its divisors is an integer number (35328853).

Almost surely, 2^131221441 is an apocalyptic number.

It is an amenable number.

131221441 is a deficient number, since it is larger than the sum of its proper divisors (10093971).

131221441 is a wasteful number, since it uses less digits than its factorization.

131221441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10093970.

The product of its digits is 192, while the sum is 19.

The square root of 131221441 is about 11455.1927526341. The cubic root of 131221441 is about 508.1613157164.

Adding to 131221441 its reverse (144122131), we get a palindrome (275343572).

The spelling of 131221441 in words is "one hundred thirty-one million, two hundred twenty-one thousand, four hundred forty-one".