20505545112 has 128 divisors (see below), whose sum is σ = 58844136960. Its totient is φ = 5898700800.

The previous prime is 20505545083. The next prime is 20505545117. The reversal of 20505545112 is 21154550502.

It is a self number, because there is not a number n which added to its sum of digits gives 20505545112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20505545117) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 788103 + ... + 813705.

It is an arithmetic number, because the mean of its divisors is an integer number (459719820).

Almost surely, 2^20505545112 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 20505545112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29422068480).

20505545112 is an abundant number, since it is smaller than the sum of its proper divisors (38338591848).

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

20505545112 is a wasteful number, since it uses less digits than its factorization.

20505545112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25793 (or 25789 counting only the distinct ones).

The product of its (nonzero) digits is 10000, while the sum is 30.

The spelling of 20505545112 in words is "twenty billion, five hundred five million, five hundred forty-five thousand, one hundred twelve".