21974400 has 288 divisors, whose sum is σ = 90433200. Its totient is φ = 4976640.

The previous prime is 21974369. The next prime is 21974413. The reversal of 21974400 is 447912.

It is a happy number.

21974400 is a `hidden beast` number, since 219 + 7 + 440 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

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, 201546 + ... + 201654.

Almost surely, 2^21974400 is an apocalyptic number.

21974400 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 21974400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45216600).

21974400 is an abundant number, since it is smaller than the sum of its proper divisors (68458800).

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

21974400 is a wasteful number, since it uses less digits than its factorization.

21974400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21974400 is about 4687.6859963099. The cubic root of 21974400 is about 280.0952057197.

The spelling of 21974400 in words is "twenty-one million, nine hundred seventy-four thousand, four hundred".