21313800 has 96 divisors (see below), whose sum is σ = 73432800. Its totient is φ = 5682240.

The previous prime is 21313793. The next prime is 21313807. The reversal of 21313800 is 831312.

It is an interprime number because it is at equal distance from previous prime (21313793) and next prime (21313807).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is not an unprimeable number, because it can be changed into a prime (21313807) 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, 3427 + ... + 7373.

It is an arithmetic number, because the mean of its divisors is an integer number (764925).

Almost surely, 2^21313800 is an apocalyptic number.

21313800 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 21313800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36716400).

21313800 is an abundant number, since it is smaller than the sum of its proper divisors (52119000).

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

21313800 is a wasteful number, since it uses less digits than its factorization.

21313800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3972 (or 3957 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 21313800 is about 4616.6871239017. The cubic root of 21313800 is about 277.2598360363.

The spelling of 21313800 in words is "twenty-one million, three hundred thirteen thousand, eight hundred".