21884540 has 24 divisors (see below), whose sum is σ = 46221840. Its totient is φ = 8703488.

The previous prime is 21884539. The next prime is 21884573. The reversal of 21884540 is 4548812.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21884497 and 21884506.

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, 524 + ... + 6636.

It is an arithmetic number, because the mean of its divisors is an integer number (1925910).

Almost surely, 2^21884540 is an apocalyptic number.

21884540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21884540 is an abundant number, since it is smaller than the sum of its proper divisors (24337300).

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

21884540 is a wasteful number, since it uses less digits than its factorization.

21884540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6301 (or 6299 counting only the distinct ones).

The product of its (nonzero) digits is 10240, while the sum is 32.

The square root of 21884540 is about 4678.0914911960. The cubic root of 21884540 is about 279.7128859639.

The spelling of 21884540 in words is "twenty-one million, eight hundred eighty-four thousand, five hundred forty".