216391699 has 2 divisors, whose sum is σ = 216391700. Its totient is φ = 216391698.

The previous prime is 216391697. The next prime is 216391757. The reversal of 216391699 is 996193612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216391699 - 2¹ = 216391697 is a prime.

It is a super-2 number, since 2×216391699² = 93650734792213202, which contains 22 as substring.

Together with 216391697, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (216391697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108195849 + 108195850.

It is an arithmetic number, because the mean of its divisors is an integer number (108195850).

Almost surely, 2^216391699 is an apocalyptic number.

216391699 is a deficient number, since it is larger than the sum of its proper divisors (1).

216391699 is an equidigital number, since it uses as much as digits as its factorization.

216391699 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 157464, while the sum is 46.

The square root of 216391699 is about 14710.2582914101. The cubic root of 216391699 is about 600.3624652467.

The spelling of 216391699 in words is "two hundred sixteen million, three hundred ninety-one thousand, six hundred ninety-nine".