131229521 has 4 divisors (see below), whose sum is σ = 132704100. Its totient is φ = 129754944.

The previous prime is 131229503. The next prime is 131229533. The reversal of 131229521 is 125922131.

It is a happy number.

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 18105025 + 113124496 = 4255^2 + 10636^2 .

It is a cyclic number.

It is not a de Polignac number, because 131229521 - 2¹⁸ = 130967377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131220521) 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, 737156 + ... + 737333.

It is an arithmetic number, because the mean of its divisors is an integer number (33176025).

Almost surely, 2^131229521 is an apocalyptic number.

It is an amenable number.

131229521 is a deficient number, since it is larger than the sum of its proper divisors (1474579).

131229521 is an equidigital number, since it uses as much as digits as its factorization.

131229521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1474578.

The product of its digits is 1080, while the sum is 26.

The square root of 131229521 is about 11455.5454256879. The cubic root of 131229521 is about 508.1717455647.

The spelling of 131229521 in words is "one hundred thirty-one million, two hundred twenty-nine thousand, five hundred twenty-one".