205056551663554 has 4 divisors (see below), whose sum is σ = 307584827495334. Its totient is φ = 102528275831776.

The previous prime is 205056551663479. The next prime is 205056551663693. The reversal of 205056551663554 is 455366155650502.

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

It can be written as a sum of positive squares in only one way, i.e., 204993812936025 + 62738727529 = 14317605^2 + 250477^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51264137915887 + ... + 51264137915890.

Almost surely, 2^{205056551663554} is an apocalyptic number.

205056551663554 is a deficient number, since it is larger than the sum of its proper divisors (102528275831780).

205056551663554 is a wasteful number, since it uses less digits than its factorization.

205056551663554 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102528275831779.

The product of its (nonzero) digits is 81000000, while the sum is 58.

The spelling of 205056551663554 in words is "two hundred five trillion, fifty-six billion, five hundred fifty-one million, six hundred sixty-three thousand, five hundred fifty-four".