82170857 has 4 divisors (see below), whose sum is σ = 82189056. Its totient is φ = 82152660.

The previous prime is 82170841. The next prime is 82170871. The reversal of 82170857 is 75807128.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 82170857 - 2⁴ = 82170841 is a prime.

It is a super-2 number, since 2×82170857² = 13504099480228898, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 82170857.

It is not an unprimeable number, because it can be changed into a prime (82170827) 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, 3368 + ... + 13254.

It is an arithmetic number, because the mean of its divisors is an integer number (20547264).

Almost surely, 2^82170857 is an apocalyptic number.

It is an amenable number.

82170857 is a deficient number, since it is larger than the sum of its proper divisors (18199).

82170857 is an equidigital number, since it uses as much as digits as its factorization.

82170857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18198.

The product of its (nonzero) digits is 31360, while the sum is 38.

The square root of 82170857 is about 9064.8142286536. The cubic root of 82170857 is about 434.7496811468.

The spelling of 82170857 in words is "eighty-two million, one hundred seventy thousand, eight hundred fifty-seven".