20112156 has 72 divisors (see below), whose sum is σ = 54840240. Its totient is φ = 6191616.

The previous prime is 20112151. The next prime is 20112179. The reversal of 20112156 is 65121102.

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 (20112151) 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, 35830 + ... + 36386.

It is an arithmetic number, because the mean of its divisors is an integer number (761670).

Almost surely, 2^20112156 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 20112156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27420120).

20112156 is an abundant number, since it is smaller than the sum of its proper divisors (34728084).

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

20112156 is a wasteful number, since it uses less digits than its factorization.

20112156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643 (or 638 counting only the distinct ones).

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

The square root of 20112156 is about 4484.6578464806. The cubic root of 20112156 is about 271.9482131800.

Adding to 20112156 its reverse (65121102), we get a palindrome (85233258).

The spelling of 20112156 in words is "twenty million, one hundred twelve thousand, one hundred fifty-six".