216719081 has 2 divisors, whose sum is σ = 216719082. Its totient is φ = 216719080.

The previous prime is 216719039. The next prime is 216719089. The reversal of 216719081 is 180917612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 204747481 + 11971600 = 14309^2 + 3460^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216719081 is a prime.

It is a super-2 number, since 2×216719081² = 93934320138969122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (216719089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108359540 + 108359541.

It is an arithmetic number, because the mean of its divisors is an integer number (108359541).

Almost surely, 2^216719081 is an apocalyptic number.

It is an amenable number.

216719081 is a deficient number, since it is larger than the sum of its proper divisors (1).

216719081 is an equidigital number, since it uses as much as digits as its factorization.

216719081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6048, while the sum is 35.

The square root of 216719081 is about 14721.3817625928. The cubic root of 216719081 is about 600.6650782532.

The spelling of 216719081 in words is "two hundred sixteen million, seven hundred nineteen thousand, eighty-one".