21385799 has 8 divisors (see below), whose sum is σ = 21919680. Its totient is φ = 20855296.

The previous prime is 21385783. The next prime is 21385801. The reversal of 21385799 is 99758312.

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 21385799 - 2⁴ = 21385783 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 (21385709) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15947 + ... + 17235.

It is an arithmetic number, because the mean of its divisors is an integer number (2739960).

Almost surely, 2^21385799 is an apocalyptic number.

21385799 is a deficient number, since it is larger than the sum of its proper divisors (533881).

21385799 is a wasteful number, since it uses less digits than its factorization.

21385799 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1689.

The product of its digits is 136080, while the sum is 44.

The square root of 21385799 is about 4624.4782408397. The cubic root of 21385799 is about 277.5716839943.

The spelling of 21385799 in words is "twenty-one million, three hundred eighty-five thousand, seven hundred ninety-nine".