21223100 has 36 divisors (see below), whose sum is σ = 46627224. Its totient is φ = 8383680.

The previous prime is 21223093. The next prime is 21223141. The reversal of 21223100 is 132212.

It is a happy number.

It is a super-2 number, since 2×21223100² = 900839947220000, which contains 22 as substring.

It is a congruent number.

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, 7022 + ... + 9578.

Almost surely, 2^21223100 is an apocalyptic number.

21223100 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 21223100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23313612).

21223100 is an abundant number, since it is smaller than the sum of its proper divisors (25404124).

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

21223100 is a wasteful number, since it uses less digits than its factorization.

21223100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2654 (or 2647 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21223100 is about 4606.8535900330. The cubic root of 21223100 is about 276.8659875588.

Adding to 21223100 its reverse (132212), we get a palindrome (21355312).

The spelling of 21223100 in words is "twenty-one million, two hundred twenty-three thousand, one hundred".