216366989 has 2 divisors, whose sum is σ = 216366990. Its totient is φ = 216366988.

The previous prime is 216366967. The next prime is 216367031. The reversal of 216366989 is 989663612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133010089 + 83356900 = 11533^2 + 9130^2 .

It is a cyclic number.

It is not a de Polignac number, because 216366989 - 2²⁴ = 199589773 is a prime.

It is a super-2 number, since 2×216366989² = 93629347857852242, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216366289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108183494 + 108183495.

It is an arithmetic number, because the mean of its divisors is an integer number (108183495).

Almost surely, 2^216366989 is an apocalyptic number.

It is an amenable number.

216366989 is a deficient number, since it is larger than the sum of its proper divisors (1).

216366989 is an equidigital number, since it uses as much as digits as its factorization.

216366989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 839808, while the sum is 50.

The square root of 216366989 is about 14709.4183773527. The cubic root of 216366989 is about 600.3396123658.

The spelling of 216366989 in words is "two hundred sixteen million, three hundred sixty-six thousand, nine hundred eighty-nine".