856642825289 has 2 divisors, whose sum is σ = 856642825290. Its totient is φ = 856642825288.

The previous prime is 856642825237. The next prime is 856642825307. The reversal of 856642825289 is 982528246658.

856642825289 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., 803739145225 + 52903680064 = 896515^2 + 230008^2 .

It is a cyclic number.

It is not a de Polignac number, because 856642825289 - 2²⁰ = 856641776713 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (856642825229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428321412644 + 428321412645.

It is an arithmetic number, because the mean of its divisors is an integer number (428321412645).

Almost surely, 2^856642825289 is an apocalyptic number.

It is an amenable number.

856642825289 is a deficient number, since it is larger than the sum of its proper divisors (1).

856642825289 is an equidigital number, since it uses as much as digits as its factorization.

856642825289 is an evil number, because the sum of its binary digits is even.

The product of its digits is 132710400, while the sum is 65.

The spelling of 856642825289 in words is "eight hundred fifty-six billion, six hundred forty-two million, eight hundred twenty-five thousand, two hundred eighty-nine".