20102105156 has 72 divisors (see below), whose sum is σ = 42869990016. Its totient is φ = 8208076800.

The previous prime is 20102105117. The next prime is 20102105197. The reversal of 20102105156 is 65150120102.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1149881 + ... + 1167231.

It is an arithmetic number, because the mean of its divisors is an integer number (595416528).

Almost surely, 2^20102105156 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 20102105156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21434995008).

20102105156 is an abundant number, since it is smaller than the sum of its proper divisors (22767884860).

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

20102105156 is a wasteful number, since it uses less digits than its factorization.

20102105156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17649 (or 17640 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

Adding to 20102105156 its reverse (65150120102), we get a palindrome (85252225258).

The spelling of 20102105156 in words is "twenty billion, one hundred two million, one hundred five thousand, one hundred fifty-six".