21885500 has 144 divisors (see below), whose sum is σ = 60750144. Its totient is φ = 6739200.

The previous prime is 21885497. The next prime is 21885527. The reversal of 21885500 is 558812.

It is a super-2 number, since 2×21885500² = 957950220500000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 591482 + ... + 591518.

It is an arithmetic number, because the mean of its divisors is an integer number (421876).

Almost surely, 2^21885500 is an apocalyptic number.

21885500 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 21885500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30375072).

21885500 is an abundant number, since it is smaller than the sum of its proper divisors (38864644).

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

21885500 is a wasteful number, since it uses less digits than its factorization.

21885500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89 (or 64 counting only the distinct ones).

The product of its (nonzero) digits is 3200, while the sum is 29.

The square root of 21885500 is about 4678.1940960161. The cubic root of 21885500 is about 279.7169759203.

The spelling of 21885500 in words is "twenty-one million, eight hundred eighty-five thousand, five hundred".