171872857 has 4 divisors (see below), whose sum is σ = 185093860. Its totient is φ = 158651856.

The previous prime is 171872819. The next prime is 171872891. The reversal of 171872857 is 758278171.

171872857 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 758278171 = 7 ⋅108325453.

It can be written as a sum of positive squares in 2 ways, for example, as 15397776 + 156475081 = 3924^2 + 12509^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-171872857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (171872257) 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, 6610482 + ... + 6610507.

It is an arithmetic number, because the mean of its divisors is an integer number (46273465).

Almost surely, 2^171872857 is an apocalyptic number.

It is an amenable number.

171872857 is a deficient number, since it is larger than the sum of its proper divisors (13221003).

171872857 is a wasteful number, since it uses less digits than its factorization.

171872857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13221002.

The product of its digits is 219520, while the sum is 46.

The square root of 171872857 is about 13110.0288710590. The cubic root of 171872857 is about 555.9927118500.

The spelling of 171872857 in words is "one hundred seventy-one million, eight hundred seventy-two thousand, eight hundred fifty-seven".