218142605 has 4 divisors (see below), whose sum is σ = 261771132. Its totient is φ = 174514080.

The previous prime is 218142583. The next prime is 218142607. The reversal of 218142605 is 506241812.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 96569929 + 121572676 = 9827^2 + 11026^2 .

It is not a de Polignac number, because 218142605 - 2¹⁴ = 218126221 is a prime.

It is a super-2 number, since 2×218142605² = 95172392232372050, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (218142607) 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, 21814256 + ... + 21814265.

It is an arithmetic number, because the mean of its divisors is an integer number (65442783).

Almost surely, 2^218142605 is an apocalyptic number.

It is an amenable number.

218142605 is a deficient number, since it is larger than the sum of its proper divisors (43628527).

218142605 is an equidigital number, since it uses as much as digits as its factorization.

218142605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43628526.

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 218142605 is about 14769.6514853940. The cubic root of 218142605 is about 601.9773697081.

The spelling of 218142605 in words is "two hundred eighteen million, one hundred forty-two thousand, six hundred five".