21996800 has 108 divisors (see below), whose sum is σ = 62350176. Its totient is φ = 7526400.

The previous prime is 21996797. The next prime is 21996803. The reversal of 21996800 is 869912.

It is an interprime number because it is at equal distance from previous prime (21996797) and next prime (21996803).

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21996803) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 44555 + ... + 45045.

Almost surely, 2^21996800 is an apocalyptic number.

21996800 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 21996800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31175088).

21996800 is an abundant number, since it is smaller than the sum of its proper divisors (40353376).

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

21996800 is an equidigital number, since it uses as much as digits as its factorization.

21996800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 524 (or 505 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 35.

The square root of 21996800 is about 4690.0746262720. The cubic root of 21996800 is about 280.1903467615.

The spelling of 21996800 in words is "twenty-one million, nine hundred ninety-six thousand, eight hundred".