216257 has 4 divisors (see below), whose sum is σ = 228996. Its totient is φ = 203520.

The previous prime is 216233. The next prime is 216259. The reversal of 216257 is 752612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 179776 + 36481 = 424^2 + 191^2 .

It is a cyclic number.

It is not a de Polignac number, because 216257 - 2¹² = 212161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216259) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6344 + ... + 6377.

It is an arithmetic number, because the mean of its divisors is an integer number (57249).

2²¹⁶²⁵⁷ is an apocalyptic number.

It is an amenable number.

216257 is a deficient number, since it is larger than the sum of its proper divisors (12739).

216257 is a wasteful number, since it uses less digits than its factorization.

216257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12738.

The product of its digits is 840, while the sum is 23.

The square root of 216257 is about 465.0344073292. The cubic root of 216257 is about 60.0237868648.

Adding to 216257 its reverse (752612), we get a palindrome (968869).

The spelling of 216257 in words is "two hundred sixteen thousand, two hundred fifty-seven".