21226859 has 4 divisors (see below), whose sum is σ = 21236160. Its totient is φ = 21217560.

The previous prime is 21226853. The next prime is 21226879. The reversal of 21226859 is 95862212.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21226859 - 2⁸ = 21226603 is a prime.

It is a super-3 number, since 3×21226859³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21226853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1382 + ... + 6660.

It is an arithmetic number, because the mean of its divisors is an integer number (5309040).

Almost surely, 2^21226859 is an apocalyptic number.

21226859 is a deficient number, since it is larger than the sum of its proper divisors (9301).

21226859 is an equidigital number, since it uses as much as digits as its factorization.

21226859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9300.

The product of its digits is 17280, while the sum is 35.

The square root of 21226859 is about 4607.2615510735. The cubic root of 21226859 is about 276.8823326075.

The spelling of 21226859 in words is "twenty-one million, two hundred twenty-six thousand, eight hundred fifty-nine".