31222428 has 12 divisors (see below), whose sum is σ = 72852360. Its totient is φ = 10407472.

The previous prime is 31222427. The next prime is 31222439. The reversal of 31222428 is 82422213.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 31222398 and 31222407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31222427) 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, 1300923 + ... + 1300946.

It is an arithmetic number, because the mean of its divisors is an integer number (6071030).

Almost surely, 2^31222428 is an apocalyptic number.

It is an amenable number.

31222428 is an abundant number, since it is smaller than the sum of its proper divisors (41629932).

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

31222428 is a wasteful number, since it uses less digits than its factorization.

31222428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2601876 (or 2601874 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 31222428 is about 5587.7032848926. The cubic root of 31222428 is about 314.8875991008.

The spelling of 31222428 in words is "thirty-one million, two hundred twenty-two thousand, four hundred twenty-eight".