856946309 has 2 divisors, whose sum is σ = 856946310. Its totient is φ = 856946308.

The previous prime is 856946297. The next prime is 856946323. The reversal of 856946309 is 903649658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 699443809 + 157502500 = 26447^2 + 12550^2 .

It is a cyclic number.

It is not a de Polignac number, because 856946309 - 2⁸ = 856946053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856946339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428473154 + 428473155.

It is an arithmetic number, because the mean of its divisors is an integer number (428473155).

Almost surely, 2^856946309 is an apocalyptic number.

It is an amenable number.

856946309 is a deficient number, since it is larger than the sum of its proper divisors (1).

856946309 is an equidigital number, since it uses as much as digits as its factorization.

856946309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1399680, while the sum is 50.

The square root of 856946309 is about 29273.6452974343. The cubic root of 856946309 is about 949.8416389773.

The spelling of 856946309 in words is "eight hundred fifty-six million, nine hundred forty-six thousand, three hundred nine".