216161611 has 4 divisors (see below), whose sum is σ = 216586800. Its totient is φ = 215736424.

The previous prime is 216161587. The next prime is 216161623. The reversal of 216161611 is 116161612.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216161611 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216161111) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 211831 + ... + 212848.

It is an arithmetic number, because the mean of its divisors is an integer number (54146700).

Almost surely, 2^216161611 is an apocalyptic number.

216161611 is a deficient number, since it is larger than the sum of its proper divisors (425189).

216161611 is an equidigital number, since it uses as much as digits as its factorization.

216161611 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425188.

The product of its digits is 432, while the sum is 25.

The square root of 216161611 is about 14702.4355465345. The cubic root of 216161611 is about 600.1496025102.

Subtracting from 216161611 its reverse (116161612), we obtain a palindrome (99999999).

The spelling of 216161611 in words is "two hundred sixteen million, one hundred sixty-one thousand, six hundred eleven".