856539539 has 2 divisors, whose sum is σ = 856539540. Its totient is φ = 856539538.

The previous prime is 856539511. The next prime is 856539547. The reversal of 856539539 is 935935658.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856539539 is a prime.

It is not a weakly prime, because it can be changed into another prime (856539839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428269769 + 428269770.

It is an arithmetic number, because the mean of its divisors is an integer number (428269770).

Almost surely, 2^856539539 is an apocalyptic number.

856539539 is a deficient number, since it is larger than the sum of its proper divisors (1).

856539539 is an equidigital number, since it uses as much as digits as its factorization.

856539539 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4374000, while the sum is 53.

The square root of 856539539 is about 29266.6967558691. The cubic root of 856539539 is about 949.6913268639.

The spelling of 856539539 in words is "eight hundred fifty-six million, five hundred thirty-nine thousand, five hundred thirty-nine".