20111216 has 20 divisors (see below), whose sum is σ = 39038424. Its totient is φ = 10036800.

The previous prime is 20111213. The next prime is 20111243. The reversal of 20111216 is 61211102.

It is a super-2 number, since 2×20111216² = 808922017997312, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20111216.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12371 + ... + 13901.

Almost surely, 2^20111216 is an apocalyptic number.

It is an amenable number.

20111216 is a deficient number, since it is larger than the sum of its proper divisors (18927208).

20111216 is a wasteful number, since it uses less digits than its factorization.

20111216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2360 (or 2354 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 14.

The square root of 20111216 is about 4484.5530435039. The cubic root of 20111216 is about 271.9439763509.

Adding to 20111216 its reverse (61211102), we get a palindrome (81322318).

The spelling of 20111216 in words is "twenty million, one hundred eleven thousand, two hundred sixteen".