216814657 has 2 divisors, whose sum is σ = 216814658. Its totient is φ = 216814656.

The previous prime is 216814607. The next prime is 216814669. The reversal of 216814657 is 756418612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 212110096 + 4704561 = 14564^2 + 2169^2 .

It is a cyclic number.

It is not a de Polignac number, because 216814657 - 2²⁷ = 82596929 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216814607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108407328 + 108407329.

It is an arithmetic number, because the mean of its divisors is an integer number (108407329).

Almost surely, 2^216814657 is an apocalyptic number.

It is an amenable number.

216814657 is a deficient number, since it is larger than the sum of its proper divisors (1).

216814657 is an equidigital number, since it uses as much as digits as its factorization.

216814657 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 40.

The square root of 216814657 is about 14724.6275674463. The cubic root of 216814657 is about 600.7533657080.

The spelling of 216814657 in words is "two hundred sixteen million, eight hundred fourteen thousand, six hundred fifty-seven".