685021349 has 2 divisors, whose sum is σ = 685021350. Its totient is φ = 685021348.

The previous prime is 685021321. The next prime is 685021357. The reversal of 685021349 is 943120586.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 680949025 + 4072324 = 26095^2 + 2018^2 .

It is a cyclic number.

It is not a de Polignac number, because 685021349 - 2¹² = 685017253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (685021319) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342510674 + 342510675.

It is an arithmetic number, because the mean of its divisors is an integer number (342510675).

Almost surely, 2^685021349 is an apocalyptic number.

It is an amenable number.

685021349 is a deficient number, since it is larger than the sum of its proper divisors (1).

685021349 is an equidigital number, since it uses as much as digits as its factorization.

685021349 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 685021349 is about 26172.9125051073. The cubic root of 685021349 is about 881.5251397543.

The spelling of 685021349 in words is "six hundred eighty-five million, twenty-one thousand, three hundred forty-nine".