205778327557 has 16 divisors (see below), whose sum is σ = 224945164800. Its totient is φ = 186688512000.

The previous prime is 205778327533. The next prime is 205778327581. The reversal of 205778327557 is 755723877502.

It is an interprime number because it is at equal distance from previous prime (205778327533) and next prime (205778327581).

It is a cyclic number.

It is not a de Polignac number, because 205778327557 - 2²³ = 205769938949 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (205778327057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11392069 + ... + 11410117.

It is an arithmetic number, because the mean of its divisors is an integer number (14059072800).

Almost surely, 2^205778327557 is an apocalyptic number.

It is an amenable number.

205778327557 is a deficient number, since it is larger than the sum of its proper divisors (19166837243).

205778327557 is a wasteful number, since it uses less digits than its factorization.

205778327557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20124.

The product of its (nonzero) digits is 28812000, while the sum is 58.

Subtracting 205778327557 from its reverse (755723877502), we obtain a palindrome (549945549945).

It can be divided in two parts, 205778 and 327557, that added together give a palindrome (533335).

The spelling of 205778327557 in words is "two hundred five billion, seven hundred seventy-eight million, three hundred twenty-seven thousand, five hundred fifty-seven".