20151216 has 30 divisors (see below), whose sum is σ = 56395820. Its totient is φ = 6717024.

The previous prime is 20151181. The next prime is 20151221. The reversal of 20151216 is 61215102.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 69826 + ... + 70113.

Almost surely, 2^20151216 is an apocalyptic number.

It is an amenable number.

20151216 is an abundant number, since it is smaller than the sum of its proper divisors (36244604).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20151216 is a wasteful number, since it uses less digits than its factorization.

20151216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139953 (or 139944 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 20151216 is about 4489.0105814088. The cubic root of 20151216 is about 272.1241503605.

Adding to 20151216 its reverse (61215102), we get a palindrome (81366318).

The spelling of 20151216 in words is "twenty million, one hundred fifty-one thousand, two hundred sixteen".