205742131100 has 144 divisors (see below), whose sum is σ = 518324637600. Its totient is φ = 70055731200.

The previous prime is 205742131099. The next prime is 205742131139. The reversal of 205742131100 is 1131247502.

It is a self number, because there is not a number n which added to its sum of digits gives 205742131100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3655976 + ... + 3711824.

It is an arithmetic number, because the mean of its divisors is an integer number (3599476650).

Almost surely, 2^205742131100 is an apocalyptic number.

205742131100 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 205742131100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (259162318800).

205742131100 is an abundant number, since it is smaller than the sum of its proper divisors (312582506500).

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

205742131100 is a wasteful number, since it uses less digits than its factorization.

205742131100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56088 (or 56081 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

Adding to 205742131100 its reverse (1131247502), we get a palindrome (206873378602).

The spelling of 205742131100 in words is "two hundred five billion, seven hundred forty-two million, one hundred thirty-one thousand, one hundred".