205530978 has 16 divisors (see below), whose sum is σ = 411392160. Its totient is φ = 68455296.

The previous prime is 205530977. The next prime is 205531019. The reversal of 205530978 is 879035502.

It is not an unprimeable number, because it can be changed into a prime (205530971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5263 + ... + 20946.

It is an arithmetic number, because the mean of its divisors is an integer number (25712010).

Almost surely, 2^205530978 is an apocalyptic number.

205530978 is an abundant number, since it is smaller than the sum of its proper divisors (205861182).

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

205530978 is a wasteful number, since it uses less digits than its factorization.

205530978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27521.

The product of its (nonzero) digits is 75600, while the sum is 39.

The square root of 205530978 is about 14336.3516279422. The cubic root of 205530978 is about 590.1454950954.

It can be divided in two parts, 2055 and 30978, that added together give a palindrome (33033).

The spelling of 205530978 in words is "two hundred five million, five hundred thirty thousand, nine hundred seventy-eight".