31322222221 has 4 divisors (see below), whose sum is σ = 31367551744. Its totient is φ = 31276892700.

The previous prime is 31322222213. The next prime is 31322222249. The reversal of 31322222221 is 12222222313.

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: 12222222313 = 7 ⋅1746031759.

It is a cyclic number.

It is not a de Polignac number, because 31322222221 - 2³ = 31322222213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31322222192 and 31322222201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31322220221) 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, 22663725 + ... + 22665106.

It is an arithmetic number, because the mean of its divisors is an integer number (7841887936).

Almost surely, 2^31322222221 is an apocalyptic number.

It is an amenable number.

31322222221 is a deficient number, since it is larger than the sum of its proper divisors (45329523).

31322222221 is an equidigital number, since it uses as much as digits as its factorization.

31322222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45329522.

The product of its digits is 1152, while the sum is 22.

Adding to 31322222221 its reverse (12222222313), we get a palindrome (43544444534).

The spelling of 31322222221 in words is "thirty-one billion, three hundred twenty-two million, two hundred twenty-two thousand, two hundred twenty-one".