20490428 has 18 divisors (see below), whose sum is σ = 41713056. Its totient is φ = 8781528.

The previous prime is 20490419. The next prime is 20490439. The reversal of 20490428 is 82409402.

It is a self number, because there is not a number n which added to its sum of digits gives 20490428.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52076 + ... + 52467.

It is an arithmetic number, because the mean of its divisors is an integer number (2317392).

Almost surely, 2^20490428 is an apocalyptic number.

20490428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20490428 is an abundant number, since it is smaller than the sum of its proper divisors (21222628).

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

20490428 is a wasteful number, since it uses less digits than its factorization.

20490428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104561 (or 104552 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 29.

The square root of 20490428 is about 4526.6353950810. The cubic root of 20490428 is about 273.6425801233.

The spelling of 20490428 in words is "twenty million, four hundred ninety thousand, four hundred twenty-eight".