216138518 has 4 divisors (see below), whose sum is σ = 324207780. Its totient is φ = 108069258.

The previous prime is 216138499. The next prime is 216138523. The reversal of 216138518 is 815831612.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54034628 + ... + 54034631.

It is an arithmetic number, because the mean of its divisors is an integer number (81051945).

Almost surely, 2^216138518 is an apocalyptic number.

216138518 is a deficient number, since it is larger than the sum of its proper divisors (108069262).

216138518 is a wasteful number, since it uses less digits than its factorization.

216138518 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108069261.

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

The square root of 216138518 is about 14701.6501794867. The cubic root of 216138518 is about 600.1282300006.

The spelling of 216138518 in words is "two hundred sixteen million, one hundred thirty-eight thousand, five hundred eighteen".