21171273 has 12 divisors (see below), whose sum is σ = 29987760. Its totient is φ = 13283392.

The previous prime is 21171253. The next prime is 21171313. The reversal of 21171273 is 37217112.

It is not a de Polignac number, because 21171273 - 2⁹ = 21170761 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21171203) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11343 + ... + 13076.

It is an arithmetic number, because the mean of its divisors is an integer number (2498980).

Almost surely, 2^21171273 is an apocalyptic number.

It is an amenable number.

21171273 is a deficient number, since it is larger than the sum of its proper divisors (8816487).

21171273 is a wasteful number, since it uses less digits than its factorization.

21171273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24456 (or 24439 counting only the distinct ones).

The product of its digits is 588, while the sum is 24.

The square root of 21171273 is about 4601.2251629322. The cubic root of 21171273 is about 276.6404341187.

Adding to 21171273 its reverse (37217112), we get a palindrome (58388385).

The spelling of 21171273 in words is "twenty-one million, one hundred seventy-one thousand, two hundred seventy-three".