685032109 has 2 divisors, whose sum is σ = 685032110. Its totient is φ = 685032108.

The previous prime is 685032041. The next prime is 685032149. The reversal of 685032109 is 901230586.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 682358884 + 2673225 = 26122^2 + 1635^2 .

It is a cyclic number.

It is not a de Polignac number, because 685032109 - 2¹³ = 685023917 is a prime.

It is equal to p_35517328 and since 685032109 and 35517328 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685032149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342516054 + 342516055.

It is an arithmetic number, because the mean of its divisors is an integer number (342516055).

Almost surely, 2^685032109 is an apocalyptic number.

It is an amenable number.

685032109 is a deficient number, since it is larger than the sum of its proper divisors (1).

685032109 is an equidigital number, since it uses as much as digits as its factorization.

685032109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 685032109 is about 26173.1180603305. The cubic root of 685032109 is about 881.5297552605.

The spelling of 685032109 in words is "six hundred eighty-five million, thirty-two thousand, one hundred nine".