21138200 has 24 divisors (see below), whose sum is σ = 49146780. Its totient is φ = 8455200.

The previous prime is 21138179. The next prime is 21138209. The reversal of 21138200 is 283112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21138209) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 52646 + ... + 53045.

Almost surely, 2^21138200 is an apocalyptic number.

21138200 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21138200 is an abundant number, since it is smaller than the sum of its proper divisors (28008580).

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

21138200 is a wasteful number, since it uses less digits than its factorization.

21138200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105707 (or 105698 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

The square root of 21138200 is about 4597.6298241594. The cubic root of 21138200 is about 276.4963064688.

The spelling of 21138200 in words is "twenty-one million, one hundred thirty-eight thousand, two hundred".