20313990 has 80 divisors (see below), whose sum is σ = 56453760. Its totient is φ = 5235840.

The previous prime is 20313989. The next prime is 20314043. The reversal of 20313990 is 9931302.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 24706 + ... + 25514.

It is an arithmetic number, because the mean of its divisors is an integer number (705672).

Almost surely, 2^20313990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20313990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28226880).

20313990 is an abundant number, since it is smaller than the sum of its proper divisors (36139770).

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

20313990 is a wasteful number, since it uses less digits than its factorization.

20313990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 859 (or 850 counting only the distinct ones).

The product of its (nonzero) digits is 1458, while the sum is 27.

The square root of 20313990 is about 4507.1043919572. The cubic root of 20313990 is about 272.8548920910.

The spelling of 20313990 in words is "twenty million, three hundred thirteen thousand, nine hundred ninety".