21101233 has 4 divisors (see below), whose sum is σ = 22342500. Its totient is φ = 19859968.

The previous prime is 21101219. The next prime is 21101243. The reversal of 21101233 is 33210112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15186609 + 5914624 = 3897^2 + 2432^2 .

It is a cyclic number.

It is not a de Polignac number, because 21101233 - 2¹³ = 21093041 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21101243) 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 3 ways as a sum of consecutive naturals, for example, 620608 + ... + 620641.

It is an arithmetic number, because the mean of its divisors is an integer number (5585625).

Almost surely, 2^21101233 is an apocalyptic number.

It is an amenable number.

21101233 is a deficient number, since it is larger than the sum of its proper divisors (1241267).

21101233 is a wasteful number, since it uses less digits than its factorization.

21101233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1241266.

The product of its (nonzero) digits is 36, while the sum is 13.

The square root of 21101233 is about 4593.6078413378. The cubic root of 21101233 is about 276.3350312555.

Adding to 21101233 its reverse (33210112), we get a palindrome (54311345).

The spelling of 21101233 in words is "twenty-one million, one hundred one thousand, two hundred thirty-three".