857640853 has 2 divisors, whose sum is σ = 857640854. Its totient is φ = 857640852.

The previous prime is 857640851. The next prime is 857640857. The reversal of 857640853 is 358046758.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 857201284 + 439569 = 29278^2 + 663^2 .

It is a cyclic number.

It is not a de Polignac number, because 857640853 - 2¹ = 857640851 is a prime.

Together with 857640851, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (857640851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428820426 + 428820427.

It is an arithmetic number, because the mean of its divisors is an integer number (428820427).

Almost surely, 2^857640853 is an apocalyptic number.

It is an amenable number.

857640853 is a deficient number, since it is larger than the sum of its proper divisors (1).

857640853 is an equidigital number, since it uses as much as digits as its factorization.

857640853 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 806400, while the sum is 46.

The square root of 857640853 is about 29285.5058518715. The cubic root of 857640853 is about 950.0981811732.

The spelling of 857640853 in words is "eight hundred fifty-seven million, six hundred forty thousand, eight hundred fifty-three".