20205506100 has 144 divisors (see below), whose sum is σ = 63756197120. Its totient is φ = 4910630400.

The previous prime is 20205506093. The next prime is 20205506131. The reversal of 20205506100 is 160550202.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 275310 + ... + 340890.

Almost surely, 2^20205506100 is an apocalyptic number.

20205506100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20205506100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31878098560).

20205506100 is an abundant number, since it is smaller than the sum of its proper divisors (43550691020).

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

20205506100 is a wasteful number, since it uses less digits than its factorization.

20205506100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65690 (or 65683 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 21.

The spelling of 20205506100 in words is "twenty billion, two hundred five million, five hundred six thousand, one hundred".