21413233 has 4 divisors (see below), whose sum is σ = 21533040. Its totient is φ = 21293428.

The previous prime is 21413221. The next prime is 21413243. The reversal of 21413233 is 33231412.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21413233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21413233.

It is not an unprimeable number, because it can be changed into a prime (21413243) 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, 59635 + ... + 59992.

It is an arithmetic number, because the mean of its divisors is an integer number (5383260).

Almost surely, 2^21413233 is an apocalyptic number.

It is an amenable number.

21413233 is a deficient number, since it is larger than the sum of its proper divisors (119807).

21413233 is a wasteful number, since it uses less digits than its factorization.

21413233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119806.

The product of its digits is 432, while the sum is 19.

The square root of 21413233 is about 4627.4434626476. The cubic root of 21413233 is about 277.6903242148.

Adding to 21413233 its reverse (33231412), we get a palindrome (54644645).

The spelling of 21413233 in words is "twenty-one million, four hundred thirteen thousand, two hundred thirty-three".