216657 has 24 divisors (see below), whose sum is σ = 378560. Its totient is φ = 116640.

The previous prime is 216653. The next prime is 216661. The reversal of 216657 is 756612.

216657 is a `hidden beast` number, since 2 + 1 + 6 + 657 = 666.

216657 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (216653) and next prime (216661).

It is not a de Polignac number, because 216657 - 2² = 216653 is a prime.

Its product of digits (2520) is a multiple of the sum of its prime divisors (210).

It is a plaindrome in base 13.

It is a zygodrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 216657.

It is not an unprimeable number, because it can be changed into a prime (216653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1107 + ... + 1287.

2²¹⁶⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

216657 is a deficient number, since it is larger than the sum of its proper divisors (161903).

216657 is a wasteful number, since it uses less digits than its factorization.

216657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 210 counting only the distinct ones).

The product of its digits is 2520, while the sum is 27.

The square root of 216657 is about 465.4642843441. The cubic root of 216657 is about 60.0607717591.

The spelling of 216657 in words is "two hundred sixteen thousand, six hundred fifty-seven".