205400344440 has 64 divisors (see below), whose sum is σ = 624001075200. Its totient is φ = 54080088192.

The previous prime is 205400344399. The next prime is 205400344447. The reversal of 205400344440 is 44443004502.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 205400344398 and 205400344407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205400344447) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10823872 + ... + 10842831.

It is an arithmetic number, because the mean of its divisors is an integer number (9750016800).

Almost surely, 2^205400344440 is an apocalyptic number.

205400344440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205400344440 is an abundant number, since it is smaller than the sum of its proper divisors (418600730760).

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

205400344440 is a wasteful number, since it uses less digits than its factorization.

205400344440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21666796 (or 21666792 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 30.

Adding to 205400344440 its reverse (44443004502), we get a palindrome (249843348942).

The spelling of 205400344440 in words is "two hundred five billion, four hundred million, three hundred forty-four thousand, four hundred forty".