20287040 has 28 divisors (see below), whose sum is σ = 48309276. Its totient is φ = 8114688.

The previous prime is 20287039. The next prime is 20287061. The reversal of 20287040 is 4078202.

It can be written as a sum of positive squares in 2 ways, for example, as 7441984 + 12845056 = 2728^2 + 3584^2 .

It is a junction number, because it is equal to n+sod(n) for n = 20286997 and 20287015.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31379 + ... + 32018.

Almost surely, 2^20287040 is an apocalyptic number.

20287040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20287040 is an abundant number, since it is smaller than the sum of its proper divisors (28022236).

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

20287040 is an equidigital number, since it uses as much as digits as its factorization.

20287040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63414 (or 63404 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 23.

The square root of 20287040 is about 4504.1136752973. The cubic root of 20287040 is about 272.7341757175.

The spelling of 20287040 in words is "twenty million, two hundred eighty-seven thousand, forty".