31923990 has 192 divisors, whose sum is σ = 105062400. Its totient is φ = 6858432.

The previous prime is 31923989. The next prime is 31924001. The reversal of 31923990 is 9932913.

It is a super-2 number, since 2×31923990² = 2038282275040200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 251307 + ... + 251433.

It is an arithmetic number, because the mean of its divisors is an integer number (547200).

Almost surely, 2^31923990 is an apocalyptic number.

31923990 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 31923990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (52531200).

31923990 is an abundant number, since it is smaller than the sum of its proper divisors (73138410).

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

31923990 is a wasteful number, since it uses less digits than its factorization.

31923990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 31923990 is about 5650.1318568685. The cubic root of 31923990 is about 317.2286395312.

The spelling of 31923990 in words is "thirty-one million, nine hundred twenty-three thousand, nine hundred ninety".