216508042 has 4 divisors (see below), whose sum is σ = 324762066. Its totient is φ = 108254020.

The previous prime is 216508031. The next prime is 216508049. The reversal of 216508042 is 240805612.

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

It can be written as a sum of positive squares in only one way, i.e., 215766721 + 741321 = 14689^2 + 861^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 216508042.

It is not an unprimeable number, because it can be changed into a prime (216508049) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 54127009 + ... + 54127012.

Almost surely, 2^216508042 is an apocalyptic number.

216508042 is a deficient number, since it is larger than the sum of its proper divisors (108254024).

216508042 is a wasteful number, since it uses less digits than its factorization.

216508042 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108254023.

The product of its (nonzero) digits is 3840, while the sum is 28.

The square root of 216508042 is about 14714.2122453090. The cubic root of 216508042 is about 600.4700409323.

It can be divided in two parts, 21650 and 8042, that added together give a palindrome (29692).

The spelling of 216508042 in words is "two hundred sixteen million, five hundred eight thousand, forty-two".