216977 has 4 divisors (see below), whose sum is σ = 220596. Its totient is φ = 213360.

The previous prime is 216973. The next prime is 216991. The reversal of 216977 is 779612.

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 15376 + 201601 = 124^2 + 449^2 .

It is a cyclic number.

It is not a de Polignac number, because 216977 - 2² = 216973 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216973) 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, 1718 + ... + 1839.

It is an arithmetic number, because the mean of its divisors is an integer number (55149).

2²¹⁶⁹⁷⁷ is an apocalyptic number.

It is an amenable number.

216977 is a deficient number, since it is larger than the sum of its proper divisors (3619).

216977 is an equidigital number, since it uses as much as digits as its factorization.

216977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3618.

The product of its digits is 5292, while the sum is 32.

The square root of 216977 is about 465.8079003194. The cubic root of 216977 is about 60.0903269122.

The spelling of 216977 in words is "two hundred sixteen thousand, nine hundred seventy-seven".