20720490 has 32 divisors (see below), whose sum is σ = 56833920. Its totient is φ = 4736064.

The previous prime is 20720459. The next prime is 20720519. The reversal of 20720490 is 9402702.

It is a self number, because there is not a number n which added to its sum of digits gives 20720490.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 49125 + ... + 49544.

It is an arithmetic number, because the mean of its divisors is an integer number (1776060).

Almost surely, 2^20720490 is an apocalyptic number.

20720490 is an abundant number, since it is smaller than the sum of its proper divisors (36113430).

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

20720490 is a wasteful number, since it uses less digits than its factorization.

20720490 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98686.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 20720490 is about 4551.9764937882. The cubic root of 20720490 is about 274.6629037592.

The spelling of 20720490 in words is "twenty million, seven hundred twenty thousand, four hundred ninety".