857811813 has 4 divisors (see below), whose sum is σ = 1143749088. Its totient is φ = 571874540.

The previous prime is 857811809. The next prime is 857811833. The reversal of 857811813 is 318118758.

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 857811813 - 2² = 857811809 is a prime.

It is a super-2 number, since 2×857811813² = 1471682213044693938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857811833) 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, 142968633 + ... + 142968638.

It is an arithmetic number, because the mean of its divisors is an integer number (285937272).

Almost surely, 2^857811813 is an apocalyptic number.

It is an amenable number.

857811813 is a deficient number, since it is larger than the sum of its proper divisors (285937275).

857811813 is a wasteful number, since it uses less digits than its factorization.

857811813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285937274.

The product of its digits is 53760, while the sum is 42.

The square root of 857811813 is about 29288.4245564694. The cubic root of 857811813 is about 950.1613070504.

The spelling of 857811813 in words is "eight hundred fifty-seven million, eight hundred eleven thousand, eight hundred thirteen".