205978636 has 24 divisors (see below), whose sum is σ = 368698176. Its totient is φ = 100660560.

The previous prime is 205978631. The next prime is 205978649. The reversal of 205978636 is 636879502.

It is a hoax number, since the sum of its digits (46) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (205978631) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 32175 + ... + 38041.

It is an arithmetic number, because the mean of its divisors is an integer number (15362424).

Almost surely, 2^205978636 is an apocalyptic number.

It is an amenable number.

205978636 is a deficient number, since it is larger than the sum of its proper divisors (162719540).

205978636 is a wasteful number, since it uses less digits than its factorization.

205978636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6069 (or 6067 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 46.

The square root of 205978636 is about 14351.9558249041. The cubic root of 205978636 is about 590.5736410685.

The spelling of 205978636 in words is "two hundred five million, nine hundred seventy-eight thousand, six hundred thirty-six".