20885240 has 32 divisors (see below), whose sum is σ = 47699280. Its totient is φ = 8228352.

The previous prime is 20885213. The next prime is 20885243. The reversal of 20885240 is 4258802.

20885240 = 1135² + 1136² + ... + 1150².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20885243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1217 + ... + 6576.

Almost surely, 2^20885240 is an apocalyptic number.

20885240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20885240 is an abundant number, since it is smaller than the sum of its proper divisors (26814040).

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

20885240 is a wasteful number, since it uses less digits than its factorization.

20885240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7871 (or 7867 counting only the distinct ones).

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

The square root of 20885240 is about 4570.0371989733. The cubic root of 20885240 is about 275.3889372633.

The spelling of 20885240 in words is "twenty million, eight hundred eighty-five thousand, two hundred forty".