21138000 has 160 divisors (see below), whose sum is σ = 73661952. Its totient is φ = 5184000.

The previous prime is 21137999. The next prime is 21138011. The reversal of 21138000 is 83112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 77865 + ... + 78135.

Almost surely, 2^21138000 is an apocalyptic number.

21138000 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 21138000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36830976).

21138000 is an abundant number, since it is smaller than the sum of its proper divisors (52523952).

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

21138000 is a wasteful number, since it uses less digits than its factorization.

21138000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 310 (or 294 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 21138000 is about 4597.6080737705. The cubic root of 21138000 is about 276.4954344387.

The spelling of 21138000 in words is "twenty-one million, one hundred thirty-eight thousand".