205716978 has 12 divisors (see below), whose sum is σ = 445720158. Its totient is φ = 68572320.

The previous prime is 205716937. The next prime is 205716989. The reversal of 205716978 is 879617502.

205716978 is a `hidden beast` number, since 2 + 0 + 571 + 6 + 9 + 78 = 666.

It can be written as a sum of positive squares in only one way, i.e., 123143409 + 82573569 = 11097^2 + 9087^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 5714343 + ... + 5714378.

Almost surely, 2^205716978 is an apocalyptic number.

205716978 is an abundant number, since it is smaller than the sum of its proper divisors (240003180).

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

205716978 is a wasteful number, since it uses less digits than its factorization.

205716978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11428729 (or 11428726 counting only the distinct ones).

The product of its (nonzero) digits is 211680, while the sum is 45.

The square root of 205716978 is about 14342.8371670322. The cubic root of 205716978 is about 590.3234633474.

The spelling of 205716978 in words is "two hundred five million, seven hundred sixteen thousand, nine hundred seventy-eight".