21576900 has 72 divisors (see below), whose sum is σ = 63370944. Its totient is φ = 5667200.

The previous prime is 21576889. The next prime is 21576911. The reversal of 21576900 is 967512.

It is an interprime number because it is at equal distance from previous prime (21576889) and next prime (21576911).

It is a super-2 number, since 2×21576900² = 931125227220000, which contains 22 as substring.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20794 + ... + 21806.

It is an arithmetic number, because the mean of its divisors is an integer number (880152).

Almost surely, 2^21576900 is an apocalyptic number.

21576900 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 21576900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31685472).

21576900 is an abundant number, since it is smaller than the sum of its proper divisors (41794044).

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

21576900 is a wasteful number, since it uses less digits than its factorization.

21576900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101 (or 1094 counting only the distinct ones).

The product of its (nonzero) digits is 3780, while the sum is 30.

The square root of 21576900 is about 4645.0941863433. The cubic root of 21576900 is about 278.3960161770.

The spelling of 21576900 in words is "twenty-one million, five hundred seventy-six thousand, nine hundred".