21358233 has 12 divisors (see below), whose sum is σ = 33224100. Its totient is φ = 13143456.

The previous prime is 21358219. The next prime is 21358241. The reversal of 21358233 is 33285312.

It can be written as a sum of positive squares in 2 ways, for example, as 8311689 + 13046544 = 2883^2 + 3612^2 .

It is not a de Polignac number, because 21358233 - 2⁵ = 21358201 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21358197 and 21358206.

It is not an unprimeable number, because it can be changed into a prime (21358133) 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 11 ways as a sum of consecutive naturals, for example, 91158 + ... + 91391.

It is an arithmetic number, because the mean of its divisors is an integer number (2768675).

Almost surely, 2^21358233 is an apocalyptic number.

It is an amenable number.

21358233 is a deficient number, since it is larger than the sum of its proper divisors (11865867).

21358233 is a wasteful number, since it uses less digits than its factorization.

21358233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 182568 (or 182565 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 21358233 is about 4621.4968354420. The cubic root of 21358233 is about 277.4523706909.

The spelling of 21358233 in words is "twenty-one million, three hundred fifty-eight thousand, two hundred thirty-three".