131021221 has 8 divisors (see below), whose sum is σ = 135442944. Its totient is φ = 126611760.

The previous prime is 131021167. The next prime is 131021239. The reversal of 131021221 is 122120131.

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

It is a cyclic number.

It is not a de Polignac number, because 131021221 - 2⁹ = 131020709 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 (131021251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22056 + ... + 27358.

It is an arithmetic number, because the mean of its divisors is an integer number (16930368).

Almost surely, 2^131021221 is an apocalyptic number.

It is an amenable number.

131021221 is a deficient number, since it is larger than the sum of its proper divisors (4421723).

131021221 is an equidigital number, since it uses as much as digits as its factorization.

131021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6131.

The product of its (nonzero) digits is 24, while the sum is 13.

The square root of 131021221 is about 11446.4501484085. The cubic root of 131021221 is about 507.9027303069.

Adding to 131021221 its reverse (122120131), we get a palindrome (253141352).

The spelling of 131021221 in words is "one hundred thirty-one million, twenty-one thousand, two hundred twenty-one".