216231611 has 4 divisors (see below), whose sum is σ = 218968800. Its totient is φ = 213494424.

The previous prime is 216231599. The next prime is 216231623. The reversal of 216231611 is 116132612.

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

It is an interprime number because it is at equal distance from previous prime (216231599) and next prime (216231623).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216231611 is a prime.

It is a super-2 number, since 2×216231611² = 93512219191310642, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (216231661) 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, 1368476 + ... + 1368633.

It is an arithmetic number, because the mean of its divisors is an integer number (54742200).

Almost surely, 2^216231611 is an apocalyptic number.

216231611 is a deficient number, since it is larger than the sum of its proper divisors (2737189).

216231611 is an equidigital number, since it uses as much as digits as its factorization.

216231611 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2737188.

The product of its digits is 432, while the sum is 23.

The square root of 216231611 is about 14704.8159118025. The cubic root of 216231611 is about 600.2143780239.

The spelling of 216231611 in words is "two hundred sixteen million, two hundred thirty-one thousand, six hundred eleven".