21800799 has 16 divisors (see below), whose sum is σ = 32371200. Its totient is φ = 14500728.

The previous prime is 21800797. The next prime is 21800819. The reversal of 21800799 is 99700812.

It is a happy number.

It is not a de Polignac number, because 21800799 - 2¹ = 21800797 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21800797) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18852 + ... + 19974.

It is an arithmetic number, because the mean of its divisors is an integer number (2023200).

Almost surely, 2^21800799 is an apocalyptic number.

21800799 is a deficient number, since it is larger than the sum of its proper divisors (10570401).

21800799 is a wasteful number, since it uses less digits than its factorization.

21800799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1851 (or 1845 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 21800799 is about 4669.1325746867. The cubic root of 21800799 is about 279.3556569645.

The spelling of 21800799 in words is "twenty-one million, eight hundred thousand, seven hundred ninety-nine".