21996450 has 72 divisors (see below), whose sum is σ = 67549248. Its totient is φ = 5027040.

The previous prime is 21996449. The next prime is 21996451. The reversal of 21996450 is 5469912.

21996450 is a `hidden beast` number, since 2 + 1 + 9 + 9 + 645 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21996449) and next prime (21996451).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21996451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 342 + ... + 6641.

It is an arithmetic number, because the mean of its divisors is an integer number (938184).

Almost surely, 2^21996450 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21996450, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33774624).

21996450 is an abundant number, since it is smaller than the sum of its proper divisors (45552798).

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

21996450 is a wasteful number, since it uses less digits than its factorization.

21996450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7008 (or 7000 counting only the distinct ones).

The product of its (nonzero) digits is 19440, while the sum is 36.

The square root of 21996450 is about 4690.0373132844. The cubic root of 21996450 is about 280.1888606796.

It can be divided in two parts, 2199 and 6450, that added together give a square (8649 = 93²).

The spelling of 21996450 in words is "twenty-one million, nine hundred ninety-six thousand, four hundred fifty".