21057200 has 60 divisors (see below), whose sum is σ = 51478848. Its totient is φ = 8275200.

The previous prime is 21057199. The next prime is 21057209. The reversal of 21057200 is 275012.

It is not an unprimeable number, because it can be changed into a prime (21057209) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23969 + ... + 24831.

Almost surely, 2^21057200 is an apocalyptic number.

21057200 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 21057200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25739424).

21057200 is an abundant number, since it is smaller than the sum of its proper divisors (30421648).

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

21057200 is a wasteful number, since it uses less digits than its factorization.

21057200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 942 (or 931 counting only the distinct ones).

The product of its (nonzero) digits is 140, while the sum is 17.

The square root of 21057200 is about 4588.8124825493. The cubic root of 21057200 is about 276.1426833483.

The spelling of 21057200 in words is "twenty-one million, fifty-seven thousand, two hundred".