21010223 has 4 divisors (see below), whose sum is σ = 22626408. Its totient is φ = 19394040.

The previous prime is 21010217. The next prime is 21010229. The reversal of 21010223 is 32201012.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (21010217) and next prime (21010229).

It is a cyclic number.

It is not a de Polignac number, because 21010223 - 2¹⁰ = 21009199 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010229) 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, 808073 + ... + 808098.

It is an arithmetic number, because the mean of its divisors is an integer number (5656602).

Almost surely, 2^21010223 is an apocalyptic number.

21010223 is a deficient number, since it is larger than the sum of its proper divisors (1616185).

21010223 is a wasteful number, since it uses less digits than its factorization.

21010223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1616184.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21010223 is about 4583.6909799855. The cubic root of 21010223 is about 275.9371793942.

Adding to 21010223 its reverse (32201012), we get a palindrome (53211235).

The spelling of 21010223 in words is "twenty-one million, ten thousand, two hundred twenty-three".