21698233 has 4 divisors (see below), whose sum is σ = 22398208. Its totient is φ = 20998260.

The previous prime is 21698213. The next prime is 21698267. The reversal of 21698233 is 33289612.

It is a happy number.

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 not a de Polignac number, because 21698233 - 2⁹ = 21697721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21698203) 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, 349941 + ... + 350002.

It is an arithmetic number, because the mean of its divisors is an integer number (5599552).

Almost surely, 2^21698233 is an apocalyptic number.

It is an amenable number.

21698233 is a deficient number, since it is larger than the sum of its proper divisors (699975).

21698233 is an equidigital number, since it uses as much as digits as its factorization.

21698233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 699974.

The product of its digits is 15552, while the sum is 34.

The square root of 21698233 is about 4658.1362152689. The cubic root of 21698233 is about 278.9168742136.

The spelling of 21698233 in words is "twenty-one million, six hundred ninety-eight thousand, two hundred thirty-three".