857917439 has 2 divisors, whose sum is σ = 857917440. Its totient is φ = 857917438.

The previous prime is 857917429. The next prime is 857917441. The reversal of 857917439 is 934719758.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 857917439 - 2¹⁶ = 857851903 is a prime.

Together with 857917441, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (857917429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428958719 + 428958720.

It is an arithmetic number, because the mean of its divisors is an integer number (428958720).

Almost surely, 2^857917439 is an apocalyptic number.

857917439 is a deficient number, since it is larger than the sum of its proper divisors (1).

857917439 is an equidigital number, since it uses as much as digits as its factorization.

857917439 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1905120, while the sum is 53.

The square root of 857917439 is about 29290.2277048165. The cubic root of 857917439 is about 950.2003045778.

The spelling of 857917439 in words is "eight hundred fifty-seven million, nine hundred seventeen thousand, four hundred thirty-nine".