21387300 has 72 divisors (see below), whose sum is σ = 67516512. Its totient is φ = 5184000.

The previous prime is 21387299. The next prime is 21387307. The reversal of 21387300 is 378312.

It is not an unprimeable number, because it can be changed into a prime (21387307) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 60 + ... + 6540.

Almost surely, 2^21387300 is an apocalyptic number.

21387300 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 21387300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33758256).

21387300 is an abundant number, since it is smaller than the sum of its proper divisors (46129212).

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

21387300 is a wasteful number, since it uses less digits than its factorization.

21387300 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6509 (or 6502 counting only the distinct ones).

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21387300 is about 4624.6405265707. The cubic root of 21387300 is about 277.5781777950.

The spelling of 21387300 in words is "twenty-one million, three hundred eighty-seven thousand, three hundred".