21885340 has 24 divisors (see below), whose sum is σ = 48378960. Its totient is φ = 8293248.

The previous prime is 21885319. The next prime is 21885361. The reversal of 21885340 is 4358812.

It is an interprime number because it is at equal distance from previous prime (21885319) and next prime (21885361).

It is a congruent number.

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, 28417 + ... + 29176.

It is an arithmetic number, because the mean of its divisors is an integer number (2015790).

Almost surely, 2^21885340 is an apocalyptic number.

21885340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21885340 is an abundant number, since it is smaller than the sum of its proper divisors (26493620).

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

21885340 is a wasteful number, since it uses less digits than its factorization.

21885340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57621 (or 57619 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 31.

The square root of 21885340 is about 4678.1769953690. The cubic root of 21885340 is about 279.7162942692.

It can be divided in two parts, 218 and 85340, that added together give a palindrome (85558).

The spelling of 21885340 in words is "twenty-one million, eight hundred eighty-five thousand, three hundred forty".