20557085818 has 16 divisors (see below), whose sum is σ = 31731300360. Its totient is φ = 9981078336.

The previous prime is 20557085761. The next prime is 20557085837. The reversal of 20557085818 is 81858075502.

It can be written as a sum of positive squares in 4 ways, for example, as 20076906249 + 480179569 = 141693^2 + 21913^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 235221 + ... + 310552.

Almost surely, 2^20557085818 is an apocalyptic number.

20557085818 is a deficient number, since it is larger than the sum of its proper divisors (11174214542).

20557085818 is a wasteful number, since it uses less digits than its factorization.

20557085818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 546321.

The product of its (nonzero) digits is 896000, while the sum is 49.

The spelling of 20557085818 in words is "twenty billion, five hundred fifty-seven million, eighty-five thousand, eight hundred eighteen".