20655105672 has 64 divisors (see below), whose sum is σ = 54914284800. Its totient is φ = 6451706880.

The previous prime is 20655105641. The next prime is 20655105673. The reversal of 20655105672 is 27650155602.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 20655105672.

It is not an unprimeable number, because it can be changed into a prime (20655105673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17104 + ... + 203967.

It is an arithmetic number, because the mean of its divisors is an integer number (858035700).

Almost surely, 2^20655105672 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 20655105672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27457142400).

20655105672 is an abundant number, since it is smaller than the sum of its proper divisors (34259179128).

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

20655105672 is a wasteful number, since it uses less digits than its factorization.

20655105672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 221326 (or 221322 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 39.

The spelling of 20655105672 in words is "twenty billion, six hundred fifty-five million, one hundred five thousand, six hundred seventy-two".