31221944 has 32 divisors (see below), whose sum is σ = 63821520. Its totient is φ = 14232576.

The previous prime is 31221937. The next prime is 31221961. The reversal of 31221944 is 44912213.

It is a Harshad number since it is a multiple of its sum of digits (26).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6824 + ... + 10440.

Almost surely, 2^31221944 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31221944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31910760).

31221944 is an abundant number, since it is smaller than the sum of its proper divisors (32599576).

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

31221944 is a wasteful number, since it uses less digits than its factorization.

31221944 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3719 (or 3715 counting only the distinct ones).

The product of its digits is 1728, while the sum is 26.

The square root of 31221944 is about 5587.6599753385. The cubic root of 31221944 is about 314.8859719971.

The spelling of 31221944 in words is "thirty-one million, two hundred twenty-one thousand, nine hundred forty-four".