21151200 has 144 divisors (see below), whose sum is σ = 78744960. Its totient is φ = 4830720.

The previous prime is 21151189. The next prime is 21151219. The reversal of 21151200 is 215112.

It is a super-2 number, since 2×21151200² = 894746522880000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16171 + ... + 17429.

It is an arithmetic number, because the mean of its divisors is an integer number (546840).

Almost surely, 2^21151200 is an apocalyptic number.

21151200 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 21151200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39372480).

21151200 is an abundant number, since it is smaller than the sum of its proper divisors (57593760).

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

21151200 is a wasteful number, since it uses less digits than its factorization.

21151200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289 (or 1276 counting only the distinct ones).

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21151200 is about 4599.0433787909. The cubic root of 21151200 is about 276.5529766263.

Adding to 21151200 its reverse (215112), we get a palindrome (21366312).

The spelling of 21151200 in words is "twenty-one million, one hundred fifty-one thousand, two hundred".