20111616 has 216 divisors, whose sum is σ = 70150080. Its totient is φ = 5419008.

The previous prime is 20111603. The next prime is 20111617. The reversal of 20111616 is 61611102.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20111617) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 467691 + ... + 467733.

Almost surely, 2^20111616 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35075040).

20111616 is an abundant number, since it is smaller than the sum of its proper divisors (50038464).

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

20111616 is a wasteful number, since it uses less digits than its factorization.

20111616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101 (or 84 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 18.

The square root of 20111616 is about 4484.5976408146. The cubic root of 20111616 is about 271.9457792730.

Adding to 20111616 its reverse (61611102), we get a palindrome (81722718).

The spelling of 20111616 in words is "twenty million, one hundred eleven thousand, six hundred sixteen".