21261200 has 60 divisors (see below), whose sum is σ = 53323968. Its totient is φ = 8131200.

The previous prime is 21261193. The next prime is 21261211. The reversal of 21261200 is 216212.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8045 + ... + 10355.

Almost surely, 2^21261200 is an apocalyptic number.

21261200 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 21261200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26661984).

21261200 is an abundant number, since it is smaller than the sum of its proper divisors (32062768).

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

21261200 is a wasteful number, since it uses less digits than its factorization.

21261200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2352 (or 2341 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

The square root of 21261200 is about 4610.9868791832. The cubic root of 21261200 is about 277.0315663870.

Adding to 21261200 its reverse (216212), we get a palindrome (21477412).

The spelling of 21261200 in words is "twenty-one million, two hundred sixty-one thousand, two hundred".