21836223 has 24 divisors (see below), whose sum is σ = 34140288. Its totient is φ = 13920984.

The previous prime is 21836219. The next prime is 21836237. The reversal of 21836223 is 32263812.

It is not a de Polignac number, because 21836223 - 2² = 21836219 is a prime.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21836203) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3636 + ... + 7542.

It is an arithmetic number, because the mean of its divisors is an integer number (1422512).

Almost surely, 2^21836223 is an apocalyptic number.

21836223 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21836223 is a deficient number, since it is larger than the sum of its proper divisors (12304065).

21836223 is an equidigital number, since it uses as much as digits as its factorization.

21836223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3945 (or 3933 counting only the distinct ones).

The product of its digits is 3456, while the sum is 27.

The square root of 21836223 is about 4672.9244590513. The cubic root of 21836223 is about 279.5068829157.

The spelling of 21836223 in words is "twenty-one million, eight hundred thirty-six thousand, two hundred twenty-three".