216506123 has 2 divisors, whose sum is σ = 216506124. Its totient is φ = 216506122.

The previous prime is 216506093. The next prime is 216506137. The reversal of 216506123 is 321605612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216506123 - 2¹⁰ = 216505099 is a prime.

It is a super-2 number, since 2×216506123² = 93749802592982258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 216506092 and 216506101.

It is not a weakly prime, because it can be changed into another prime (216506183) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108253061 + 108253062.

It is an arithmetic number, because the mean of its divisors is an integer number (108253062).

Almost surely, 2^216506123 is an apocalyptic number.

216506123 is a deficient number, since it is larger than the sum of its proper divisors (1).

216506123 is an equidigital number, since it uses as much as digits as its factorization.

216506123 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 216506123 is about 14714.1470361010. The cubic root of 216506123 is about 600.4682668559.

The spelling of 216506123 in words is "two hundred sixteen million, five hundred six thousand, one hundred twenty-three".