218163666781438 has 32 divisors (see below), whose sum is σ = 380338169713920. Its totient is φ = 91912923046080.

The previous prime is 218163666781427. The next prime is 218163666781447. The reversal of 218163666781438 is 834187666361812.

It is a super-2 number, since 2×218163666781438² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 71761345 + ... + 74739667.

It is an arithmetic number, because the mean of its divisors is an integer number (11885567803560).

Almost surely, 2^{218163666781438} is an apocalyptic number.

218163666781438 is a deficient number, since it is larger than the sum of its proper divisors (162174502932482).

218163666781438 is a wasteful number, since it uses less digits than its factorization.

218163666781438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3067072.

The product of its digits is 334430208, while the sum is 70.

The spelling of 218163666781438 in words is "two hundred eighteen trillion, one hundred sixty-three billion, six hundred sixty-six million, seven hundred eighty-one thousand, four hundred thirty-eight".