42170857 has 4 divisors (see below), whose sum is σ = 42216336. Its totient is φ = 42125380.

The previous prime is 42170851. The next prime is 42170867. The reversal of 42170857 is 75807124.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 42170857 - 2⁷ = 42170729 is a prime.

It is a super-2 number, since 2×42170857² = 3556762360228898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42170851) 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, 21319 + ... + 23212.

It is an arithmetic number, because the mean of its divisors is an integer number (10554084).

Almost surely, 2^42170857 is an apocalyptic number.

It is an amenable number.

42170857 is a deficient number, since it is larger than the sum of its proper divisors (45479).

42170857 is an equidigital number, since it uses as much as digits as its factorization.

42170857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45478.

The product of its (nonzero) digits is 15680, while the sum is 34.

The square root of 42170857 is about 6493.9092232645. The cubic root of 42170857 is about 348.0733787440.

The spelling of 42170857 in words is "forty-two million, one hundred seventy thousand, eight hundred fifty-seven".