21838700 has 72 divisors (see below), whose sum is σ = 51840432. Its totient is φ = 7937280.

The previous prime is 21838679. The next prime is 21838723. The reversal of 21838700 is 783812.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139022 + ... + 139178.

It is an arithmetic number, because the mean of its divisors is an integer number (720006).

Almost surely, 2^21838700 is an apocalyptic number.

21838700 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 21838700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25920216).

21838700 is an abundant number, since it is smaller than the sum of its proper divisors (30001732).

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

21838700 is a wasteful number, since it uses less digits than its factorization.

21838700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291 (or 284 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21838700 is about 4673.1894889893. The cubic root of 21838700 is about 279.5174511715.

The spelling of 21838700 in words is "twenty-one million, eight hundred thirty-eight thousand, seven hundred".