218913873 has 4 divisors (see below), whose sum is σ = 291885168. Its totient is φ = 145942580.

The previous prime is 218913859. The next prime is 218913881. The reversal of 218913873 is 378319812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 218913873 - 2⁶ = 218913809 is a prime.

It is not an unprimeable number, because it can be changed into a prime (218913173) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36485643 + ... + 36485648.

It is an arithmetic number, because the mean of its divisors is an integer number (72971292).

Almost surely, 2^218913873 is an apocalyptic number.

It is an amenable number.

218913873 is a deficient number, since it is larger than the sum of its proper divisors (72971295).

218913873 is an equidigital number, since it uses as much as digits as its factorization.

218913873 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72971294.

The product of its digits is 72576, while the sum is 42.

The square root of 218913873 is about 14795.7383391300. The cubic root of 218913873 is about 602.6859883901.

The spelling of 218913873 in words is "two hundred eighteen million, nine hundred thirteen thousand, eight hundred seventy-three".