21382273 has 6 divisors (see below), whose sum is σ = 23502962. Its totient is φ = 19438320.

The previous prime is 21382271. The next prime is 21382297. The reversal of 21382273 is 37228312.

It can be written as a sum of positive squares in only one way, i.e., 15944049 + 5438224 = 3993^2 + 2332^2 .

It is not a de Polignac number, because 21382273 - 2¹ = 21382271 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 (21382271) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 88236 + ... + 88477.

Almost surely, 2^21382273 is an apocalyptic number.

It is an amenable number.

21382273 is a deficient number, since it is larger than the sum of its proper divisors (2120689).

21382273 is a wasteful number, since it uses less digits than its factorization.

21382273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 176735 (or 176724 counting only the distinct ones).

The product of its digits is 4032, while the sum is 28.

The square root of 21382273 is about 4624.0969929274. The cubic root of 21382273 is about 277.5564282078.

The spelling of 21382273 in words is "twenty-one million, three hundred eighty-two thousand, two hundred seventy-three".