856386109 has 2 divisors, whose sum is σ = 856386110. Its totient is φ = 856386108.

The previous prime is 856386103. The next prime is 856386217. The reversal of 856386109 is 901683658.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 529138009 + 327248100 = 23003^2 + 18090^2 .

It is a cyclic number.

It is not a de Polignac number, because 856386109 - 2¹⁵ = 856353341 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856386103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428193054 + 428193055.

It is an arithmetic number, because the mean of its divisors is an integer number (428193055).

Almost surely, 2^856386109 is an apocalyptic number.

It is an amenable number.

856386109 is a deficient number, since it is larger than the sum of its proper divisors (1).

856386109 is an equidigital number, since it uses as much as digits as its factorization.

856386109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 856386109 is about 29264.0753997115. The cubic root of 856386109 is about 949.6346181210.

The spelling of 856386109 in words is "eight hundred fifty-six million, three hundred eighty-six thousand, one hundred nine".