31222220 has 12 divisors (see below), whose sum is σ = 65566704. Its totient is φ = 12488880.

The previous prime is 31222211. The next prime is 31222249. The reversal of 31222220 is 2222213.

It is a junction number, because it is equal to n+sod(n) for n = 31222195 and 31222204.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 780536 + ... + 780575.

It is an arithmetic number, because the mean of its divisors is an integer number (5463892).

Almost surely, 2^31222220 is an apocalyptic number.

It is an amenable number.

31222220 is an abundant number, since it is smaller than the sum of its proper divisors (34344484).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31222220 is a wasteful number, since it uses less digits than its factorization.

31222220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561120 (or 1561118 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 31222220 is about 5587.6846725634. The cubic root of 31222220 is about 314.8868998517.

Adding to 31222220 its reverse (2222213), we get a palindrome (33444433).

The spelling of 31222220 in words is "thirty-one million, two hundred twenty-two thousand, two hundred twenty".