31839990 has 128 divisors (see below), whose sum is σ = 95800320. Its totient is φ = 6594048.

The previous prime is 31839989. The next prime is 31840001. The reversal of 31839990 is 9993813.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 292056 + ... + 292164.

It is an arithmetic number, because the mean of its divisors is an integer number (748440).

Almost surely, 2^31839990 is an apocalyptic number.

31839990 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 31839990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47900160).

31839990 is an abundant number, since it is smaller than the sum of its proper divisors (63960330).

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

31839990 is a wasteful number, since it uses less digits than its factorization.

31839990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 246.

The product of its (nonzero) digits is 52488, while the sum is 42.

The square root of 31839990 is about 5642.6935057648. The cubic root of 31839990 is about 316.9501591807.

The spelling of 31839990 in words is "thirty-one million, eight hundred thirty-nine thousand, nine hundred ninety".