131221433 has 8 divisors (see below), whose sum is σ = 155138880. Its totient is φ = 108596880.

The previous prime is 131221411. The next prime is 131221439. The reversal of 131221433 is 334122131.

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

It is not a de Polignac number, because 131221433 - 2⁸ = 131221177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131221439) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 323003 + ... + 323408.

It is an arithmetic number, because the mean of its divisors is an integer number (19392360).

Almost surely, 2^131221433 is an apocalyptic number.

It is an amenable number.

131221433 is a deficient number, since it is larger than the sum of its proper divisors (23917447).

131221433 is an equidigital number, since it uses as much as digits as its factorization.

131221433 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 646447.

The product of its digits is 432, while the sum is 20.

The square root of 131221433 is about 11455.1924034474. The cubic root of 131221433 is about 508.1613053896.

Adding to 131221433 its reverse (334122131), we get a palindrome (465343564).

The spelling of 131221433 in words is "one hundred thirty-one million, two hundred twenty-one thousand, four hundred thirty-three".