21226173 has 16 divisors (see below), whose sum is σ = 30820800. Its totient is φ = 12942720.

The previous prime is 21226157. The next prime is 21226181. The reversal of 21226173 is 37162212.

It is not a de Polignac number, because 21226173 - 2⁴ = 21226157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21226193) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4768 + ... + 8073.

It is an arithmetic number, because the mean of its divisors is an integer number (1926300).

Almost surely, 2^21226173 is an apocalyptic number.

It is an amenable number.

21226173 is a deficient number, since it is larger than the sum of its proper divisors (9594627).

21226173 is a wasteful number, since it uses less digits than its factorization.

21226173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12892.

The product of its digits is 1008, while the sum is 24.

The square root of 21226173 is about 4607.1871027776. The cubic root of 21226173 is about 276.8793498562.

Adding to 21226173 its reverse (37162212), we get a palindrome (58388385).

The spelling of 21226173 in words is "twenty-one million, two hundred twenty-six thousand, one hundred seventy-three".