21799789 has 8 divisors (see below), whose sum is σ = 24549120. Its totient is φ = 19178400.

The previous prime is 21799781. The next prime is 21799819. The reversal of 21799789 is 98799712.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21799789 - 2³ = 21799781 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21799781) 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 7 ways as a sum of consecutive naturals, for example, 31624 + ... + 32305.

It is an arithmetic number, because the mean of its divisors is an integer number (3068640).

Almost surely, 2^21799789 is an apocalyptic number.

It is an amenable number.

21799789 is a deficient number, since it is larger than the sum of its proper divisors (2749331).

21799789 is a wasteful number, since it uses less digits than its factorization.

21799789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63971.

The product of its digits is 571536, while the sum is 52.

The square root of 21799789 is about 4669.0244162994. The cubic root of 21799789 is about 279.3513428478.

The spelling of 21799789 in words is "twenty-one million, seven hundred ninety-nine thousand, seven hundred eighty-nine".