31722990 has 48 divisors (see below), whose sum is σ = 82455408. Its totient is φ = 7807488.

The previous prime is 31722983. The next prime is 31723009. The reversal of 31722990 is 9922713.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1942 + ... + 8198.

It is an arithmetic number, because the mean of its divisors is an integer number (1717821).

Almost surely, 2^31722990 is an apocalyptic number.

31722990 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 31722990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41227704).

31722990 is an abundant number, since it is smaller than the sum of its proper divisors (50732418).

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

31722990 is a wasteful number, since it uses less digits than its factorization.

31722990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6293 (or 6280 counting only the distinct ones).

The product of its (nonzero) digits is 6804, while the sum is 33.

The square root of 31722990 is about 5632.3165749095. The cubic root of 31722990 is about 316.5614584324.

The spelling of 31722990 in words is "thirty-one million, seven hundred twenty-two thousand, nine hundred ninety".