20028040 has 32 divisors (see below), whose sum is σ = 47715480. Its totient is φ = 7539712.

The previous prime is 20028031. The next prime is 20028053. The reversal of 20028040 is 4082002.

It can be written as a sum of positive squares in 4 ways, for example, as 17994564 + 2033476 = 4242^2 + 1426^2 .

It is a super-2 number, since 2×20028040² = 802244772483200, which contains 22 as substring.

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, 14047 + ... + 15406.

Almost surely, 2^20028040 is an apocalyptic number.

20028040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20028040 is an abundant number, since it is smaller than the sum of its proper divisors (27687440).

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

20028040 is a wasteful number, since it uses less digits than its factorization.

20028040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29481 (or 29477 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 16.

The square root of 20028040 is about 4475.2698242676. The cubic root of 20028040 is about 271.5685562059.

The spelling of 20028040 in words is "twenty million, twenty-eight thousand, forty".