857407217 has 4 divisors (see below), whose sum is σ = 858766656. Its totient is φ = 856047780.

The previous prime is 857407193. The next prime is 857407219. The reversal of 857407217 is 712704758.

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 an emirpimes, since its reverse is a distinct semiprime: 712704758 = 2 ⋅356352379.

It is a cyclic number.

It is not a de Polignac number, because 857407217 - 2⁸ = 857406961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (857407219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 678773 + ... + 680034.

It is an arithmetic number, because the mean of its divisors is an integer number (214691664).

Almost surely, 2^857407217 is an apocalyptic number.

It is an amenable number.

857407217 is a deficient number, since it is larger than the sum of its proper divisors (1359439).

857407217 is a wasteful number, since it uses less digits than its factorization.

857407217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1359438.

The product of its (nonzero) digits is 109760, while the sum is 41.

The square root of 857407217 is about 29281.5166444636. The cubic root of 857407217 is about 950.0118990199.

The spelling of 857407217 in words is "eight hundred fifty-seven million, four hundred seven thousand, two hundred seventeen".