857012561 has 2 divisors, whose sum is σ = 857012562. Its totient is φ = 857012560.

The previous prime is 857012549. The next prime is 857012567. The reversal of 857012561 is 165210758.

857012561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 730674961 + 126337600 = 27031^2 + 11240^2 .

It is a cyclic number.

It is not a de Polignac number, because 857012561 - 2¹⁴ = 856996177 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (857012567) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428506280 + 428506281.

It is an arithmetic number, because the mean of its divisors is an integer number (428506281).

Almost surely, 2^857012561 is an apocalyptic number.

It is an amenable number.

857012561 is a deficient number, since it is larger than the sum of its proper divisors (1).

857012561 is an equidigital number, since it uses as much as digits as its factorization.

857012561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 35.

The square root of 857012561 is about 29274.7768736160. The cubic root of 857012561 is about 949.8661163127.

The spelling of 857012561 in words is "eight hundred fifty-seven million, twelve thousand, five hundred sixty-one".