217272445 has 16 divisors (see below), whose sum is σ = 283277232. Its totient is φ = 159022080.

The previous prime is 217272443. The next prime is 217272463. The reversal of 217272445 is 544272712.

It can be written as a sum of positive squares in 8 ways, for example, as 43586404 + 173686041 = 6602^2 + 13179^2 .

It is not a de Polignac number, because 217272445 - 2¹ = 217272443 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 217272445.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (217272443) 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, 7446 + ... + 22135.

It is an arithmetic number, because the mean of its divisors is an integer number (17704827).

Almost surely, 2^217272445 is an apocalyptic number.

It is an amenable number.

217272445 is a deficient number, since it is larger than the sum of its proper divisors (66004787).

217272445 is a wasteful number, since it uses less digits than its factorization.

217272445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29712.

The product of its digits is 31360, while the sum is 34.

The square root of 217272445 is about 14740.1643477948. The cubic root of 217272445 is about 601.1758838048.

The spelling of 217272445 in words is "two hundred seventeen million, two hundred seventy-two thousand, four hundred forty-five".