857142409 has 2 divisors, whose sum is σ = 857142410. Its totient is φ = 857142408.

The previous prime is 857142401. The next prime is 857142523. The reversal of 857142409 is 904241758.

857142409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 519612025 + 337530384 = 22795^2 + 18372^2 .

It is a cyclic number.

It is not a de Polignac number, because 857142409 - 2³ = 857142401 is a prime.

It is not a weakly prime, because it can be changed into another prime (857142401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428571204 + 428571205.

It is an arithmetic number, because the mean of its divisors is an integer number (428571205).

Almost surely, 2^857142409 is an apocalyptic number.

It is an amenable number.

857142409 is a deficient number, since it is larger than the sum of its proper divisors (1).

857142409 is an equidigital number, since it uses as much as digits as its factorization.

857142409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80640, while the sum is 40.

The square root of 857142409 is about 29276.9945349587. The cubic root of 857142409 is about 949.9140860440.

The spelling of 857142409 in words is "eight hundred fifty-seven million, one hundred forty-two thousand, four hundred nine".