20191216 has 40 divisors (see below), whose sum is σ = 40466160. Its totient is φ = 9755136.

The previous prime is 20191181. The next prime is 20191231. The reversal of 20191216 is 61219102.

20191216 is nontrivially palindromic in base 15.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68766 + ... + 69058.

It is an arithmetic number, because the mean of its divisors is an integer number (1011654).

Almost surely, 2^20191216 is an apocalyptic number.

It is an amenable number.

20191216 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

20191216 is a wasteful number, since it uses less digits than its factorization.

20191216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 433 (or 427 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 22.

The square root of 20191216 is about 4493.4636974165. The cubic root of 20191216 is about 272.3040860984.

The spelling of 20191216 in words is "twenty million, one hundred ninety-one thousand, two hundred sixteen".