205638713280 has 2688 divisors, whose sum is σ = 1028107468800. Its totient is φ = 37523865600.

The previous prime is 205638713261. The next prime is 205638713383. The reversal of 205638713280 is 82317836502.

205638713280 is a `hidden beast` number, since 2 + 0 + 5 + 638 + 7 + 1 + 3 + 2 + 8 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 3485401891 + ... + 3485401949.

Almost surely, 2^205638713280 is an apocalyptic number.

205638713280 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 205638713280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (514053734400).

205638713280 is an abundant number, since it is smaller than the sum of its proper divisors (822468755520).

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

205638713280 is a wasteful number, since it uses less digits than its factorization.

205638713280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 160 (or 131 counting only the distinct ones).

The product of its (nonzero) digits is 483840, while the sum is 45.

The spelling of 205638713280 in words is "two hundred five billion, six hundred thirty-eight million, seven hundred thirteen thousand, two hundred eighty".