31122201221 has 4 divisors (see below), whose sum is σ = 31123231200. Its totient is φ = 31121171244.

The previous prime is 31122201211. The next prime is 31122201251. The reversal of 31122201221 is 12210222113.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12210222113 = 40471 ⋅301703.

It is a cyclic number.

It is not a de Polignac number, because 31122201221 - 2³⁴ = 13942332037 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 31122201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31122201211) 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, 468251 + ... + 530568.

It is an arithmetic number, because the mean of its divisors is an integer number (7780807800).

Almost surely, 2^31122201221 is an apocalyptic number.

It is an amenable number.

31122201221 is a deficient number, since it is larger than the sum of its proper divisors (1029979).

31122201221 is an equidigital number, since it uses as much as digits as its factorization.

31122201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1029978.

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 31122201221 its reverse (12210222113), we get a palindrome (43332423334).

The spelling of 31122201221 in words is "thirty-one billion, one hundred twenty-two million, two hundred one thousand, two hundred twenty-one".