205978428539136 has 648 divisors, whose sum is σ = 673788186271200. Its totient is φ = 60013810483200.

The previous prime is 205978428539129. The next prime is 205978428539159. The reversal of 205978428539136 is 631935824879502.

205978428539136 is a `hidden beast` number, since 2 + 0 + 5 + 9 + 7 + 84 + 2 + 8 + 539 + 1 + 3 + 6 = 666.

It is a super-2 number, since 2×205978428539136² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5136727215 + ... + 5136767313.

It is a 1-persistent number, because it is pandigital, but 2⋅205978428539136 = 411956857078272 is not.

Almost surely, 2^{205978428539136} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 205978428539136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (336894093135600).

205978428539136 is an abundant number, since it is smaller than the sum of its proper divisors (467809757732064).

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

205978428539136 is a wasteful number, since it uses less digits than its factorization.

205978428539136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40431 (or 40385 counting only the distinct ones).

The product of its (nonzero) digits is 783820800, while the sum is 72.

The spelling of 205978428539136 in words is "two hundred five trillion, nine hundred seventy-eight billion, four hundred twenty-eight million, five hundred thirty-nine thousand, one hundred thirty-six".