21385800 has 108 divisors (see below), whose sum is σ = 72485595. Its totient is φ = 5650560.

The previous prime is 21385783. The next prime is 21385801. The reversal of 21385800 is 858312.

It is a happy number.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 5 ways, for example, as 11985444 + 9400356 = 3462^2 + 3066^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=3270.

It is not an unprimeable number, because it can be changed into a prime (21385801) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 196146 + ... + 196254.

Almost surely, 2^21385800 is an apocalyptic number.

21385800 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 21385800

21385800 is an abundant number, since it is smaller than the sum of its proper divisors (51099795).

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

21385800 is a wasteful number, since it uses less digits than its factorization.

21385800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 240 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 21385800 is about 4624.4783489600. The cubic root of 21385800 is about 277.5716883207.

The spelling of 21385800 in words is "twenty-one million, three hundred eighty-five thousand, eight hundred".