20428580 has 12 divisors (see below), whose sum is σ = 42900060. Its totient is φ = 8171424.

The previous prime is 20428579. The next prime is 20428589. The reversal of 20428580 is 8582402.

It can be written as a sum of positive squares in 2 ways, for example, as 3912484 + 16516096 = 1978^2 + 4064^2 .

It is not an unprimeable number, because it can be changed into a prime (20428589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 510695 + ... + 510734.

It is an arithmetic number, because the mean of its divisors is an integer number (3575005).

Almost surely, 2^20428580 is an apocalyptic number.

20428580 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20428580 is an abundant number, since it is smaller than the sum of its proper divisors (22471480).

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

20428580 is a wasteful number, since it uses less digits than its factorization.

20428580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1021438 (or 1021436 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 29.

The square root of 20428580 is about 4519.7986680825. The cubic root of 20428580 is about 273.3669831003.

The spelling of 20428580 in words is "twenty million, four hundred twenty-eight thousand, five hundred eighty".