20490775 has 12 divisors (see below), whose sum is σ = 26029584. Its totient is φ = 15992000.

The previous prime is 20490761. The next prime is 20490787. The reversal of 20490775 is 57709402.

It is not a de Polignac number, because 20490775 - 2¹⁵ = 20458007 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20490775.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8971 + ... + 11020.

It is an arithmetic number, because the mean of its divisors is an integer number (2169132).

Almost surely, 2^20490775 is an apocalyptic number.

20490775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20490775 is a deficient number, since it is larger than the sum of its proper divisors (5538809).

20490775 is a wasteful number, since it uses less digits than its factorization.

20490775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20042 (or 20037 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 34.

The square root of 20490775 is about 4526.6737236077. The cubic root of 20490775 is about 273.6441248029.

The spelling of 20490775 in words is "twenty million, four hundred ninety thousand, seven hundred seventy-five".