1685335021 has 2 divisors, whose sum is σ = 1685335022. Its totient is φ = 1685335020.

The previous prime is 1685334953. The next prime is 1685335031. The reversal of 1685335021 is 1205335861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1647954025 + 37380996 = 40595^2 + 6114^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685335021 - 2⁹ = 1685334509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1685335031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842667510 + 842667511.

It is an arithmetic number, because the mean of its divisors is an integer number (842667511).

Almost surely, 2^1685335021 is an apocalyptic number.

It is an amenable number.

1685335021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685335021 is an equidigital number, since it uses as much as digits as its factorization.

1685335021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 1685335021 is about 41052.8320703944. The cubic root of 1685335021 is about 1190.0414318367.

The spelling of 1685335021 in words is "one billion, six hundred eighty-five million, three hundred thirty-five thousand, twenty-one".