20280408 has 16 divisors (see below), whose sum is σ = 50701080. Its totient is φ = 6760128.

The previous prime is 20280401. The next prime is 20280413. The reversal of 20280408 is 80408202.

It is a super-2 number, since 2×20280408² = 822589897292928, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 845017 = 20280408 / (2 + 0 + 2 + 8 + 0 + 4 + 0 + 8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20280401) 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, 422485 + ... + 422532.

Almost surely, 2^20280408 is an apocalyptic number.

It is an amenable number.

20280408 is an abundant number, since it is smaller than the sum of its proper divisors (30420672).

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

20280408 is a wasteful number, since it uses less digits than its factorization.

20280408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 845026 (or 845022 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 20280408 is about 4503.3773992416. The cubic root of 20280408 is about 272.7044527977.

The spelling of 20280408 in words is "twenty million, two hundred eighty thousand, four hundred eight".