216345511 has 2 divisors, whose sum is σ = 216345512. Its totient is φ = 216345510.

The previous prime is 216345491. The next prime is 216345517. The reversal of 216345511 is 115543612.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216345511 is a prime.

It is a super-2 number, since 2×216345511² = 93610760259702242, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 216345511.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (216345517) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 108172755 + 108172756.

It is an arithmetic number, because the mean of its divisors is an integer number (108172756).

Almost surely, 2^216345511 is an apocalyptic number.

216345511 is a deficient number, since it is larger than the sum of its proper divisors (1).

216345511 is an equidigital number, since it uses as much as digits as its factorization.

216345511 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 28.

The square root of 216345511 is about 14708.6882827804. The cubic root of 216345511 is about 600.3197471652.

It can be divided in two parts, 2163 and 45511, that added together give a palindrome (47674).

The spelling of 216345511 in words is "two hundred sixteen million, three hundred forty-five thousand, five hundred eleven".