218731923 has 6 divisors (see below), whose sum is σ = 315946124. Its totient is φ = 145821276.

The previous prime is 218731913. The next prime is 218731943. The reversal of 218731923 is 329137812.

It is not a de Polignac number, because 218731923 - 2⁴ = 218731907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218731913) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12151765 + ... + 12151782.

Almost surely, 2^218731923 is an apocalyptic number.

218731923 is a deficient number, since it is larger than the sum of its proper divisors (97214201).

218731923 is a wasteful number, since it uses less digits than its factorization.

218731923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24303553 (or 24303550 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 218731923 is about 14789.5883309847. The cubic root of 218731923 is about 602.5189681993.

The spelling of 218731923 in words is "two hundred eighteen million, seven hundred thirty-one thousand, nine hundred twenty-three".