857538991 has 4 divisors (see below), whose sum is σ = 857601112. Its totient is φ = 857476872.

The previous prime is 857538977. The next prime is 857539009. The reversal of 857538991 is 199835758.

857538991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

857538991 is a nontrivial binomial coefficient, being equal to C(41414, 2).

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a 3-Lehmer number, since φ(857538991) divides (857538991-1)³.

It is a cyclic number.

It is not a de Polignac number, because 857538991 - 2²⁹ = 320668079 is a prime.

It is a super-3 number, since 3×857538991³ (a number of 28 digits) contains 333 as substring.

It is a deceptive number, since it divides R_857538990.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (857538791) 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, 1 + ... + 41413.

It is an arithmetic number, because the mean of its divisors is an integer number (214400278).

Almost surely, 2^857538991 is an apocalyptic number.

857538991 is the 41413-rd triangular number and also the 20707-th hexagonal number.

857538991 is the 13805-th centered nonagonal number.

857538991 is a deficient number, since it is larger than the sum of its proper divisors (62121).

857538991 is a wasteful number, since it uses less digits than its factorization.

857538991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62120.

The product of its digits is 2721600, while the sum is 55.

The square root of 857538991 is about 29283.7666805348. The cubic root of 857538991 is about 950.0605652984.

The spelling of 857538991 in words is "eight hundred fifty-seven million, five hundred thirty-eight thousand, nine hundred ninety-one".