218865131 has 4 divisors (see below), whose sum is σ = 218979264. Its totient is φ = 218751000.

The previous prime is 218865121. The next prime is 218865137. The reversal of 218865131 is 131568812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-218865131 is a prime.

It is a super-2 number, since 2×218865131² = 95803891135294322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 218865091 and 218865100.

It is not an unprimeable number, because it can be changed into a prime (218865137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54140 + ... + 58041.

It is an arithmetic number, because the mean of its divisors is an integer number (54744816).

Almost surely, 2^218865131 is an apocalyptic number.

218865131 is a deficient number, since it is larger than the sum of its proper divisors (114133).

218865131 is a wasteful number, since it uses less digits than its factorization.

218865131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 114132.

The product of its digits is 11520, while the sum is 35.

The square root of 218865131 is about 14794.0910839429. The cubic root of 218865131 is about 602.6412549666.

The spelling of 218865131 in words is "two hundred eighteen million, eight hundred sixty-five thousand, one hundred thirty-one".