205278558987 has 4 divisors (see below), whose sum is σ = 273704745320. Its totient is φ = 136852372656.

The previous prime is 205278558983. The next prime is 205278559021. The reversal of 205278558987 is 789855872502.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 205278558987 - 2² = 205278558983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205278558983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 34213093162 + ... + 34213093167.

It is an arithmetic number, because the mean of its divisors is an integer number (68426186330).

Almost surely, 2^205278558987 is an apocalyptic number.

205278558987 is a deficient number, since it is larger than the sum of its proper divisors (68426186333).

205278558987 is an equidigital number, since it uses as much as digits as its factorization.

205278558987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68426186332.

The product of its (nonzero) digits is 112896000, while the sum is 66.

The spelling of 205278558987 in words is "two hundred five billion, two hundred seventy-eight million, five hundred fifty-eight thousand, nine hundred eighty-seven".