218214693 has 12 divisors (see below), whose sum is σ = 316106700. Its totient is φ = 145057536.

The previous prime is 218214653. The next prime is 218214707. The reversal of 218214693 is 396412812.

It can be written as a sum of positive squares in 2 ways, for example, as 142993764 + 75220929 = 11958^2 + 8673^2 .

It is not a de Polignac number, because 218214693 - 2⁹ = 218214181 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218214613) 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 in 11 ways as a sum of consecutive naturals, for example, 31596 + ... + 37877.

It is an arithmetic number, because the mean of its divisors is an integer number (26342225).

Almost surely, 2^218214693 is an apocalyptic number.

It is an amenable number.

218214693 is a deficient number, since it is larger than the sum of its proper divisors (97892007).

218214693 is a wasteful number, since it uses less digits than its factorization.

218214693 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69828 (or 69825 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 218214693 is about 14772.0916934603. The cubic root of 218214693 is about 602.0436727660.

The spelling of 218214693 in words is "two hundred eighteen million, two hundred fourteen thousand, six hundred ninety-three".