1685359821 has 8 divisors (see below), whose sum is σ = 2379331584. Its totient is φ = 1057480640.

The previous prime is 1685359747. The next prime is 1685359829. The reversal of 1685359821 is 1289535861.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1685359821 - 2¹⁵ = 1685327053 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1685359829) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16523085 + ... + 16523186.

It is an arithmetic number, because the mean of its divisors is an integer number (297416448).

Almost surely, 2^1685359821 is an apocalyptic number.

It is an amenable number.

1685359821 is a deficient number, since it is larger than the sum of its proper divisors (693971763).

1685359821 is a wasteful number, since it uses less digits than its factorization.

1685359821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33046291.

The product of its digits is 518400, while the sum is 48.

The square root of 1685359821 is about 41053.1341190901. The cubic root of 1685359821 is about 1190.0472690307.

The spelling of 1685359821 in words is "one billion, six hundred eighty-five million, three hundred fifty-nine thousand, eight hundred twenty-one".