218112731 has 2 divisors, whose sum is σ = 218112732. Its totient is φ = 218112730.

The previous prime is 218112709. The next prime is 218112757. The reversal of 218112731 is 137211812.

It is an a-pointer prime, because the next prime (218112757) can be obtained adding 218112731 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 218112731 - 2⁶ = 218112667 is a prime.

It is a super-2 number, since 2×218112731² = 95146326848556722, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 218112731.

It is not a weakly prime, because it can be changed into another prime (218112701) 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, 109056365 + 109056366.

It is an arithmetic number, because the mean of its divisors is an integer number (109056366).

Almost surely, 2^218112731 is an apocalyptic number.

218112731 is a deficient number, since it is larger than the sum of its proper divisors (1).

218112731 is an equidigital number, since it uses as much as digits as its factorization.

218112731 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 672, while the sum is 26.

The square root of 218112731 is about 14768.6401202006. The cubic root of 218112731 is about 601.9498887660.

It can be divided in two parts, 21811 and 2731, that added together give a palindrome (24542).

The spelling of 218112731 in words is "two hundred eighteen million, one hundred twelve thousand, seven hundred thirty-one".