216776669 has 2 divisors, whose sum is σ = 216776670. Its totient is φ = 216776668.

The previous prime is 216776627. The next prime is 216776699. The reversal of 216776669 is 966677612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 175880644 + 40896025 = 13262^2 + 6395^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216776669 is a prime.

It is a super-2 number, since 2×216776669² = 93984248445471122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen 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 (216776699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108388334 + 108388335.

It is an arithmetic number, because the mean of its divisors is an integer number (108388335).

Almost surely, 2^216776669 is an apocalyptic number.

It is an amenable number.

216776669 is a deficient number, since it is larger than the sum of its proper divisors (1).

216776669 is an equidigital number, since it uses as much as digits as its factorization.

216776669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1143072, while the sum is 50.

The square root of 216776669 is about 14723.3375632022. The cubic root of 216776669 is about 600.7182777483.

The spelling of 216776669 in words is "two hundred sixteen million, seven hundred seventy-six thousand, six hundred sixty-nine".