31221402 has 32 divisors (see below), whose sum is σ = 64826880. Its totient is φ = 10013760.

The previous prime is 31221383. The next prime is 31221403. The reversal of 31221402 is 20412213.

It is not an unprimeable number, because it can be changed into a prime (31221403) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42228 + ... + 42960.

It is an arithmetic number, because the mean of its divisors is an integer number (2025840).

Almost surely, 2^31221402 is an apocalyptic number.

31221402 is an abundant number, since it is smaller than the sum of its proper divisors (33605478).

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

31221402 is a wasteful number, since it uses less digits than its factorization.

31221402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 998.

The product of its (nonzero) digits is 96, while the sum is 15.

The square root of 31221402 is about 5587.6114753981. The cubic root of 31221402 is about 314.8841498899.

Adding to 31221402 its reverse (20412213), we get a palindrome (51633615).

The spelling of 31221402 in words is "thirty-one million, two hundred twenty-one thousand, four hundred two".