205138977 has 8 divisors (see below), whose sum is σ = 274331616. Its totient is φ = 136352832.

The previous prime is 205138961. The next prime is 205138987. The reversal of 205138977 is 779831502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205138977 - 2⁴ = 205138961 is a prime.

It is not an unprimeable number, because it can be changed into a prime (205138907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 100443 + ... + 102464.

It is an arithmetic number, because the mean of its divisors is an integer number (34291452).

Almost surely, 2^205138977 is an apocalyptic number.

It is an amenable number.

205138977 is a deficient number, since it is larger than the sum of its proper divisors (69192639).

205138977 is a wasteful number, since it uses less digits than its factorization.

205138977 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203247.

The product of its (nonzero) digits is 105840, while the sum is 42.

The square root of 205138977 is about 14322.6735283605. The cubic root of 205138977 is about 589.7700693628.

The spelling of 205138977 in words is "two hundred five million, one hundred thirty-eight thousand, nine hundred seventy-seven".