21318700 has 108 divisors (see below), whose sum is σ = 53760448. Its totient is φ = 7286400.

The previous prime is 21318691. The next prime is 21318709. The reversal of 21318700 is 781312.

It is an interprime number because it is at equal distance from previous prime (21318691) and next prime (21318709).

It is not an unprimeable number, because it can be changed into a prime (21318709) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 687685 + ... + 687715.

Almost surely, 2^21318700 is an apocalyptic number.

21318700 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 21318700, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26880224).

21318700 is an abundant number, since it is smaller than the sum of its proper divisors (32441748).

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

21318700 is a wasteful number, since it uses less digits than its factorization.

21318700 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 22.

The square root of 21318700 is about 4617.2177769735. The cubic root of 21318700 is about 277.2810815689.

The spelling of 21318700 in words is "twenty-one million, three hundred eighteen thousand, seven hundred".