212728717 has 8 divisors (see below), whose sum is σ = 220240440. Its totient is φ = 205228800.

The previous prime is 212728699. The next prime is 212728729. The reversal of 212728717 is 717827212.

It can be written as a sum of positive squares in 4 ways, for example, as 181476 + 212547241 = 426^2 + 14579^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212728717 - 2¹⁵ = 212695949 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 (212728517) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50193 + ... + 54265.

It is an arithmetic number, because the mean of its divisors is an integer number (27530055).

Almost surely, 2^212728717 is an apocalyptic number.

It is an amenable number.

212728717 is a deficient number, since it is larger than the sum of its proper divisors (7511723).

212728717 is a wasteful number, since it uses less digits than its factorization.

212728717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5903.

The product of its digits is 21952, while the sum is 37.

The square root of 212728717 is about 14585.2225557240. Note that the first 3 decimals coincide. The cubic root of 212728717 is about 596.9556132341.

The spelling of 212728717 in words is "two hundred twelve million, seven hundred twenty-eight thousand, seven hundred seventeen".