218308913 has 8 divisors (see below), whose sum is σ = 226705920. Its totient is φ = 209996640.

The previous prime is 218308903. The next prime is 218308919. The reversal of 218308913 is 319803812.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 218308913 - 2¹⁸ = 218046769 is a prime.

It is a super-4 number, since 4×218308913⁴ (a number of 34 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (218308919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15908 + ... + 26261.

It is an arithmetic number, because the mean of its divisors is an integer number (28338240).

Almost surely, 2^218308913 is an apocalyptic number.

It is an amenable number.

218308913 is a deficient number, since it is larger than the sum of its proper divisors (8397007).

218308913 is a wasteful number, since it uses less digits than its factorization.

218308913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42367.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 218308913 is about 14775.2804711112. The cubic root of 218308913 is about 602.1303097563.

The spelling of 218308913 in words is "two hundred eighteen million, three hundred eight thousand, nine hundred thirteen".