856659389 has 2 divisors, whose sum is σ = 856659390. Its totient is φ = 856659388.

The previous prime is 856659383. The next prime is 856659413. The reversal of 856659389 is 983956658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 806844025 + 49815364 = 28405^2 + 7058^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856659389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856659383) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428329694 + 428329695.

It is an arithmetic number, because the mean of its divisors is an integer number (428329695).

Almost surely, 2^856659389 is an apocalyptic number.

It is an amenable number.

856659389 is a deficient number, since it is larger than the sum of its proper divisors (1).

856659389 is an equidigital number, since it uses as much as digits as its factorization.

856659389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13996800, while the sum is 59.

The square root of 856659389 is about 29268.7442333968. The cubic root of 856659389 is about 949.7356195058.

The spelling of 856659389 in words is "eight hundred fifty-six million, six hundred fifty-nine thousand, three hundred eighty-nine".