21232400 has 60 divisors (see below), whose sum is σ = 58305792. Its totient is φ = 7278720.

The previous prime is 21232399. The next prime is 21232429. The reversal of 21232400 is 423212.

It is a Harshad number since it is a multiple of its sum of digits (14).

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, 992 + ... + 6591.

Almost surely, 2^21232400 is an apocalyptic number.

21232400 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 21232400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29152896).

21232400 is an abundant number, since it is smaller than the sum of its proper divisors (37073392).

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

21232400 is a wasteful number, since it uses less digits than its factorization.

21232400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7608 (or 7597 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 14.

The square root of 21232400 is about 4607.8628451810. The cubic root of 21232400 is about 276.9064227085.

Subtracting from 21232400 its sum of digits (14), we obtain a triangular number (21232386 = T₆₅₁₆).

Adding to 21232400 its reverse (423212), we get a palindrome (21655612).

The spelling of 21232400 in words is "twenty-one million, two hundred thirty-two thousand, four hundred".