205609972386 has 256 divisors, whose sum is σ = 572545290240. Its totient is φ = 47626444800.

The previous prime is 205609972357. The next prime is 205609972417. The reversal of 205609972386 is 683279906502.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is an unprimeable number.

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 127 ways as a sum of consecutive naturals, for example, 11807286 + ... + 11824686.

It is an arithmetic number, because the mean of its divisors is an integer number (2236505040).

Almost surely, 2^205609972386 is an apocalyptic number.

205609972386 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 205609972386, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (286272645120).

205609972386 is an abundant number, since it is smaller than the sum of its proper divisors (366935317854).

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

205609972386 is a wasteful number, since it uses less digits than its factorization.

205609972386 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17529.

The product of its (nonzero) digits is 9797760, while the sum is 57.

The spelling of 205609972386 in words is "two hundred five billion, six hundred nine million, nine hundred seventy-two thousand, three hundred eighty-six".