21994773600 has 72 divisors (see below), whose sum is σ = 71592995880. Its totient is φ = 5865272320.

The previous prime is 21994773539. The next prime is 21994773611. The reversal of 21994773600 is 637749912.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a self number, because there is not a number n which added to its sum of digits gives 21994773600.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4579845 + ... + 4584644.

It is an arithmetic number, because the mean of its divisors is an integer number (994347165).

Almost surely, 2^21994773600 is an apocalyptic number.

21994773600 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21994773600 is an abundant number, since it is smaller than the sum of its proper divisors (49598222280).

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

21994773600 is a wasteful number, since it uses less digits than its factorization.

21994773600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9164512 (or 9164499 counting only the distinct ones).

The product of its (nonzero) digits is 571536, while the sum is 48.

The spelling of 21994773600 in words is "twenty-one billion, nine hundred ninety-four million, seven hundred seventy-three thousand, six hundred".