218931007 has 2 divisors, whose sum is σ = 218931008. Its totient is φ = 218931006.

The previous prime is 218930993. The next prime is 218931047. The reversal of 218931007 is 700139812.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218931007 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 218931007.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (218931047) 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, 109465503 + 109465504.

It is an arithmetic number, because the mean of its divisors is an integer number (109465504).

Almost surely, 2^218931007 is an apocalyptic number.

218931007 is a deficient number, since it is larger than the sum of its proper divisors (1).

218931007 is an equidigital number, since it uses as much as digits as its factorization.

218931007 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 218931007 is about 14796.3173458804. The cubic root of 218931007 is about 602.7017117005.

It can be divided in two parts, 218 and 931007, that added together give a square (931225 = 965²).

The spelling of 218931007 in words is "two hundred eighteen million, nine hundred thirty-one thousand, seven".