205780356 has 72 divisors (see below), whose sum is σ = 560361984. Its totient is φ = 63486720.

The previous prime is 205780339. The next prime is 205780361. The reversal of 205780356 is 653087502.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 205780356.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21660 + ... + 29676.

Almost surely, 2^205780356 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 205780356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (280180992).

205780356 is an abundant number, since it is smaller than the sum of its proper divisors (354581628).

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

205780356 is a wasteful number, since it uses less digits than its factorization.

205780356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8081 (or 8076 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 205780356 is about 14345.0463923962. The cubic root of 205780356 is about 590.3840800894.

The spelling of 205780356 in words is "two hundred five million, seven hundred eighty thousand, three hundred fifty-six".