21096900 has 108 divisors (see below), whose sum is σ = 72172464. Its totient is φ = 5112000.

The previous prime is 21096883. The next prime is 21096913. The reversal of 21096900 is 969012.

It is a happy number.

It is a super-2 number, since 2×21096900² = 890158379220000, which contains 22 as substring.

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 35 ways as a sum of consecutive naturals, for example, 8835 + ... + 10965.

Almost surely, 2^21096900 is an apocalyptic number.

21096900 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 21096900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36086232).

21096900 is an abundant number, since it is smaller than the sum of its proper divisors (51075564).

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

21096900 is a wasteful number, since it uses less digits than its factorization.

21096900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2162 (or 2152 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 21096900 is about 4593.1361834807. The cubic root of 21096900 is about 276.3161154311.

It can be divided in two parts, 2109 and 6900, that added together give a palindrome (9009).

The spelling of 21096900 in words is "twenty-one million, ninety-six thousand, nine hundred".