216911938 has 16 divisors (see below), whose sum is σ = 337148280. Its totient is φ = 104541696.

The previous prime is 216911927. The next prime is 216911939. The reversal of 216911938 is 839119612.

It can be written as a sum of positive squares in 4 ways, for example, as 208600249 + 8311689 = 14443^2 + 2883^2 .

It is a super-3 number, since 3×216911938³ (a number of 26 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 216911938.

It is not an unprimeable number, because it can be changed into a prime (216911939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36256 + ... + 41812.

Almost surely, 2^216911938 is an apocalyptic number.

216911938 is a deficient number, since it is larger than the sum of its proper divisors (120236342).

216911938 is a wasteful number, since it uses less digits than its factorization.

216911938 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6261.

The product of its digits is 23328, while the sum is 40.

The square root of 216911938 is about 14727.9305403033. The cubic root of 216911938 is about 600.8432015007.

The spelling of 216911938 in words is "two hundred sixteen million, nine hundred eleven thousand, nine hundred thirty-eight".