20990320 has 40 divisors (see below), whose sum is σ = 52559136. Its totient is φ = 7749888.

The previous prime is 20990311. The next prime is 20990353. The reversal of 20990320 is 2309902.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (25) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9052 + ... + 11131.

Almost surely, 2^20990320 is an apocalyptic number.

20990320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20990320 is an abundant number, since it is smaller than the sum of its proper divisors (31568816).

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

20990320 is a wasteful number, since it uses less digits than its factorization.

20990320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20209 (or 20203 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 25.

The square root of 20990320 is about 4581.5193986275. The cubic root of 20990320 is about 275.8500200341.

The spelling of 20990320 in words is "twenty million, nine hundred ninety thousand, three hundred twenty".