216840023 has 2 divisors, whose sum is σ = 216840024. Its totient is φ = 216840022.

The previous prime is 216840011. The next prime is 216840061. The reversal of 216840023 is 320048612.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 216840023 - 2⁴ = 216840007 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216839974 and 216840001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216840623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108420011 + 108420012.

It is an arithmetic number, because the mean of its divisors is an integer number (108420012).

Almost surely, 2^216840023 is an apocalyptic number.

216840023 is a deficient number, since it is larger than the sum of its proper divisors (1).

216840023 is an equidigital number, since it uses as much as digits as its factorization.

216840023 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 216840023 is about 14725.4888883188. The cubic root of 216840023 is about 600.7767929612.

Adding to 216840023 its reverse (320048612), we get a palindrome (536888635).

The spelling of 216840023 in words is "two hundred sixteen million, eight hundred forty thousand, twenty-three".