205411403640 has 64 divisors (see below), whose sum is σ = 618241599360. Its totient is φ = 54597939840.

The previous prime is 205411403551. The next prime is 205411403647. The reversal of 205411403640 is 46304114502.

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 = 205411403598 and 205411403607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205411403647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2751046 + ... + 2824725.

It is an arithmetic number, because the mean of its divisors is an integer number (9660024990).

Almost surely, 2^205411403640 is an apocalyptic number.

205411403640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

205411403640 is an abundant number, since it is smaller than the sum of its proper divisors (412830195720).

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

205411403640 is a wasteful number, since it uses less digits than its factorization.

205411403640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5576092 (or 5576088 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 30.

The spelling of 205411403640 in words is "two hundred five billion, four hundred eleven million, four hundred three thousand, six hundred forty".