20021122156 has 192 divisors, whose sum is σ = 45984153600. Its totient is φ = 7426298880.

The previous prime is 20021122097. The next prime is 20021122157. The reversal of 20021122156 is 65122112002.

It is not an unprimeable number, because it can be changed into a prime (20021122157) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 33423945 + ... + 33424543.

It is an arithmetic number, because the mean of its divisors is an integer number (239500800).

Almost surely, 2^20021122156 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 20021122156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22992076800).

20021122156 is an abundant number, since it is smaller than the sum of its proper divisors (25963031444).

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

20021122156 is a wasteful number, since it uses less digits than its factorization.

20021122156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 764 (or 762 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 22.

Adding to 20021122156 its reverse (65122112002), we get a palindrome (85143234158).

The spelling of 20021122156 in words is "twenty billion, twenty-one million, one hundred twenty-two thousand, one hundred fifty-six".