21868600 has 72 divisors (see below), whose sum is σ = 55141560. Its totient is φ = 8062080.

The previous prime is 21868597. The next prime is 21868603. The reversal of 21868600 is 686812.

It is an interprime number because it is at equal distance from previous prime (21868597) and next prime (21868603).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21868603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 33477 + ... + 34123.

It is an arithmetic number, because the mean of its divisors is an integer number (765855).

Almost surely, 2^21868600 is an apocalyptic number.

21868600 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 21868600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27570780).

21868600 is an abundant number, since it is smaller than the sum of its proper divisors (33272960).

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

21868600 is a wasteful number, since it uses less digits than its factorization.

21868600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 689 (or 667 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 21868600 is about 4676.3874946373. The cubic root of 21868600 is about 279.6449581582.

The spelling of 21868600 in words is "twenty-one million, eight hundred sixty-eight thousand, six hundred".