257817171049 has 3 divisors (see below), whose sum is σ = 257817678807. Its totient is φ = 257816663292.

The previous prime is 257817171043. The next prime is 257817171071. The reversal of 257817171049 is 940171718752.

The square root of 257817171049 is 507757.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 199992312025 + 57824859024 = 447205^2 + 240468^2 .

It is not a de Polignac number, because 257817171049 - 2⁹ = 257817170537 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 257817170987 and 257817171005.

It is not an unprimeable number, because it can be changed into a prime (257817171043) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 253879 + ... + 761635.

It is an arithmetic number, because the mean of its divisors is an integer number (85939226269).

Almost surely, 2^257817171049 is an apocalyptic number.

257817171049 is the 507757-th square number.

257817171049 is the 253879-th centered octagonal number.

It is an amenable number.

257817171049 is a deficient number, since it is larger than the sum of its proper divisors (507758).

257817171049 is an frugal number, since it uses more digits than its factorization.

257817171049 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1015514 (or 507757 counting only the distinct ones).

The product of its (nonzero) digits is 987840, while the sum is 52.

The spelling of 257817171049 in words is "two hundred fifty-seven billion, eight hundred seventeen million, one hundred seventy-one thousand, forty-nine".