205401240100 has 144 divisors (see below), whose sum is σ = 532231934976. Its totient is φ = 67274064000.

The previous prime is 205401239987. The next prime is 205401240103. The reversal of 205401240100 is 1042104502.

It is not an unprimeable number, because it can be changed into a prime (205401240103) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13049235 + ... + 13064965.

It is an arithmetic number, because the mean of its divisors is an integer number (3696055104).

Almost surely, 2^205401240100 is an apocalyptic number.

205401240100 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 205401240100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266115967488).

205401240100 is an abundant number, since it is smaller than the sum of its proper divisors (326830694876).

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

205401240100 is a wasteful number, since it uses less digits than its factorization.

205401240100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16586 (or 16579 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

Adding to 205401240100 its reverse (1042104502), we get a palindrome (206443344602).

The spelling of 205401240100 in words is "two hundred five billion, four hundred one million, two hundred forty thousand, one hundred".