205556814257 has 4 divisors (see below), whose sum is σ = 205604745060. Its totient is φ = 205508883456.

The previous prime is 205556814241. The next prime is 205556814277. The reversal of 205556814257 is 752418655502.

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

It can be written as a sum of positive squares in 2 ways, for example, as 144883764496 + 60673049761 = 380636^2 + 246319^2 .

It is a cyclic number.

It is not a de Polignac number, because 205556814257 - 2⁴ = 205556814241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (205556814277) 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, 23958968 + ... + 23967545.

It is an arithmetic number, because the mean of its divisors is an integer number (51401186265).

Almost surely, 2^205556814257 is an apocalyptic number.

It is an amenable number.

205556814257 is a deficient number, since it is larger than the sum of its proper divisors (47930803).

205556814257 is an equidigital number, since it uses as much as digits as its factorization.

205556814257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47930802.

The product of its (nonzero) digits is 3360000, while the sum is 50.

The spelling of 205556814257 in words is "two hundred five billion, five hundred fifty-six million, eight hundred fourteen thousand, two hundred fifty-seven".