20408790 has 16 divisors (see below), whose sum is σ = 48981168. Its totient is φ = 5442336.

The previous prime is 20408783. The next prime is 20408807. The reversal of 20408790 is 9780402.

It is a Harshad number since it is a multiple of its sum of digits (30), and also a Moran number because the ratio is a prime number: 680293 = 20408790 / (2 + 0 + 4 + 0 + 8 + 7 + 9 + 0).

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, 340117 + ... + 340176.

It is an arithmetic number, because the mean of its divisors is an integer number (3061323).

Almost surely, 2^20408790 is an apocalyptic number.

20408790 is an abundant number, since it is smaller than the sum of its proper divisors (28572378).

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

20408790 is a wasteful number, since it uses less digits than its factorization.

20408790 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680303.

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 20408790 is about 4517.6088808129. The cubic root of 20408790 is about 273.2786806587.

The spelling of 20408790 in words is "twenty million, four hundred eight thousand, seven hundred ninety".