131221541 has 4 divisors (see below), whose sum is σ = 143150784. Its totient is φ = 119292300.

The previous prime is 131221537. The next prime is 131221547. The reversal of 131221541 is 145122131.

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 a cyclic number.

It is not a de Polignac number, because 131221541 - 2² = 131221537 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 (131221547) 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, 5964605 + ... + 5964626.

It is an arithmetic number, because the mean of its divisors is an integer number (35787696).

Almost surely, 2^131221541 is an apocalyptic number.

131221541 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

131221541 is a deficient number, since it is larger than the sum of its proper divisors (11929243).

131221541 is a wasteful number, since it uses less digits than its factorization.

131221541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11929242.

The product of its digits is 240, while the sum is 20.

The square root of 131221541 is about 11455.1971174659. The cubic root of 131221541 is about 508.1614448013.

Adding to 131221541 its reverse (145122131), we get a palindrome (276343672).

The spelling of 131221541 in words is "one hundred thirty-one million, two hundred twenty-one thousand, five hundred forty-one".