857943643 has 4 divisors (see below), whose sum is σ = 870748840. Its totient is φ = 845138448.

The previous prime is 857943617. The next prime is 857943673. The reversal of 857943643 is 346349758.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 346349758 = 2 ⋅173174879.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-857943643 is a prime.

It is a super-2 number, since 2×857943643² = 1472134589128222898, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (857943673) 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, 6402498 + ... + 6402631.

It is an arithmetic number, because the mean of its divisors is an integer number (217687210).

Almost surely, 2^857943643 is an apocalyptic number.

857943643 is a deficient number, since it is larger than the sum of its proper divisors (12805197).

857943643 is a wasteful number, since it uses less digits than its factorization.

857943643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12805196.

The product of its digits is 2177280, while the sum is 49.

The square root of 857943643 is about 29290.6750178278. The cubic root of 857943643 is about 950.2099787004.

The spelling of 857943643 in words is "eight hundred fifty-seven million, nine hundred forty-three thousand, six hundred forty-three".