21198859 has 8 divisors (see below), whose sum is σ = 23182128. Its totient is φ = 19224960.

The previous prime is 21198857. The next prime is 21198869. The reversal of 21198859 is 95889112.

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 21198859 - 2¹ = 21198857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21198857) 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, 2919 + ... + 7135.

It is an arithmetic number, because the mean of its divisors is an integer number (2897766).

Almost surely, 2^21198859 is an apocalyptic number.

21198859 is a deficient number, since it is larger than the sum of its proper divisors (1983269).

21198859 is a wasteful number, since it uses less digits than its factorization.

21198859 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4685.

The product of its digits is 51840, while the sum is 43.

The square root of 21198859 is about 4604.2218669391. The cubic root of 21198859 is about 276.7605353971.

The spelling of 21198859 in words is "twenty-one million, one hundred ninety-eight thousand, eight hundred fifty-nine".