216539111 has 2 divisors, whose sum is σ = 216539112. Its totient is φ = 216539110.

The previous prime is 216539101. The next prime is 216539117. The reversal of 216539111 is 111935612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 216539111 - 2¹⁸ = 216276967 is a prime.

It is equal to p_11942525 and since 216539111 and 11942525 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216539117) 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, 108269555 + 108269556.

It is an arithmetic number, because the mean of its divisors is an integer number (108269556).

Almost surely, 2^216539111 is an apocalyptic number.

216539111 is a deficient number, since it is larger than the sum of its proper divisors (1).

216539111 is an equidigital number, since it uses as much as digits as its factorization.

216539111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1620, while the sum is 29.

The square root of 216539111 is about 14715.2679554264. The cubic root of 216539111 is about 600.4987621309.

The spelling of 216539111 in words is "two hundred sixteen million, five hundred thirty-nine thousand, one hundred eleven".