131201221 has 4 divisors (see below), whose sum is σ = 132998572. Its totient is φ = 129403872.

The previous prime is 131201197. The next prime is 131201243. The reversal of 131201221 is 122102131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122102131 = 9209 ⋅13259.

It can be written as a sum of positive squares in 2 ways, for example, as 110544196 + 20657025 = 10514^2 + 4545^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-131201221 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 (131201261) 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, 898566 + ... + 898711.

It is an arithmetic number, because the mean of its divisors is an integer number (33249643).

Almost surely, 2^131201221 is an apocalyptic number.

It is an amenable number.

131201221 is a deficient number, since it is larger than the sum of its proper divisors (1797351).

131201221 is an equidigital number, since it uses as much as digits as its factorization.

131201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1797350.

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

The square root of 131201221 is about 11454.3101494590. The cubic root of 131201221 is about 508.1352134028.

Adding to 131201221 its reverse (122102131), we get a palindrome (253303352).

It can be divided in two parts, 13120 and 1221, that added together give a palindrome (14341).

The spelling of 131201221 in words is "one hundred thirty-one million, two hundred one thousand, two hundred twenty-one".