215863 has 2 divisors, whose sum is σ = 215864. Its totient is φ = 215862.

The previous prime is 215857. The next prime is 215893. The reversal of 215863 is 368512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 215863 - 2⁹ = 215351 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (215833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107931 + 107932.

It is an arithmetic number, because the mean of its divisors is an integer number (107932).

2²¹⁵⁸⁶³ is an apocalyptic number.

215863 is a deficient number, since it is larger than the sum of its proper divisors (1).

215863 is an equidigital number, since it uses as much as digits as its factorization.

215863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 25.

The square root of 215863 is about 464.6105896339. The cubic root of 215863 is about 59.9873121320.

The spelling of 215863 in words is "two hundred fifteen thousand, eight hundred sixty-three".