21840522 has 16 divisors (see below), whose sum is σ = 47652192. Its totient is φ = 6618320.

The previous prime is 21840521. The next prime is 21840541. The reversal of 21840522 is 22504812.

It is a junction number, because it is equal to n+sod(n) for n = 21840492 and 21840501.

It is not an unprimeable number, because it can be changed into a prime (21840521) 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, 165393 + ... + 165524.

It is an arithmetic number, because the mean of its divisors is an integer number (2978262).

Almost surely, 2^21840522 is an apocalyptic number.

21840522 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21840522 is an abundant number, since it is smaller than the sum of its proper divisors (25811670).

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

21840522 is a wasteful number, since it uses less digits than its factorization.

21840522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330933.

The product of its (nonzero) digits is 1280, while the sum is 24.

The square root of 21840522 is about 4673.3844267297. The cubic root of 21840522 is about 279.5252243239.

The spelling of 21840522 in words is "twenty-one million, eight hundred forty thousand, five hundred twenty-two".