21824868 has 48 divisors (see below), whose sum is σ = 56623616. Its totient is φ = 6497280.

The previous prime is 21824851. The next prime is 21824879. The reversal of 21824868 is 86842812.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2580 + ... + 7092.

Almost surely, 2^21824868 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21824868, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28311808).

21824868 is an abundant number, since it is smaller than the sum of its proper divisors (34798748).

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

21824868 is a wasteful number, since it uses less digits than its factorization.

21824868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4564 (or 4562 counting only the distinct ones).

The product of its digits is 49152, while the sum is 39.

The square root of 21824868 is about 4671.7093231493. The cubic root of 21824868 is about 279.4584259557.

The spelling of 21824868 in words is "twenty-one million, eight hundred twenty-four thousand, eight hundred sixty-eight".