20880240 has 120 divisors (see below), whose sum is σ = 68598288. Its totient is φ = 5253120.

The previous prime is 20880191. The next prime is 20880257. The reversal of 20880240 is 4208802.

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20880240.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 86520 + ... + 86760.

Almost surely, 2^20880240 is an apocalyptic number.

20880240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20880240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34299144).

20880240 is an abundant number, since it is smaller than the sum of its proper divisors (47718048).

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

20880240 is a wasteful number, since it uses less digits than its factorization.

20880240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 295 (or 270 counting only the distinct ones).

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

The square root of 20880240 is about 4569.4901247295. The cubic root of 20880240 is about 275.3669591489.

The spelling of 20880240 in words is "twenty million, eight hundred eighty thousand, two hundred forty".