21438200 has 48 divisors (see below), whose sum is σ = 56968080. Its totient is φ = 7349760.

The previous prime is 21438187. The next prime is 21438211. The reversal of 21438200 is 283412.

21438200 = 914² + 915² + ... + 938².

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6257 + ... + 9056.

It is an arithmetic number, because the mean of its divisors is an integer number (1186835).

Almost surely, 2^21438200 is an apocalyptic number.

21438200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21438200 is an abundant number, since it is smaller than the sum of its proper divisors (35529880).

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

21438200 is a wasteful number, since it uses less digits than its factorization.

21438200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15336 (or 15327 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21438200 is about 4630.1403866406. The cubic root of 21438200 is about 277.7982076826.

The spelling of 21438200 in words is "twenty-one million, four hundred thirty-eight thousand, two hundred".