1685956236021 has 12 divisors (see below), whose sum is σ = 2435298266700. Its totient is φ = 1123957832640.

The previous prime is 1685956236017. The next prime is 1685956236049. The reversal of 1685956236021 is 1206326595861.

1685956236021 is a `hidden beast` number, since 1 + 6 + 8 + 5 + 9 + 5 + 6 + 23 + 602 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 287200599921 + 1398755636100 = 535911^2 + 1182690^2 .

It is not a de Polignac number, because 1685956236021 - 2² = 1685956236017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1685956236121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 224946 + ... + 1850003.

It is an arithmetic number, because the mean of its divisors is an integer number (202941522225).

Almost surely, 2^{1685956236021} is an apocalyptic number.

It is an amenable number.

1685956236021 is a deficient number, since it is larger than the sum of its proper divisors (749342030679).

1685956236021 is a wasteful number, since it uses less digits than its factorization.

1685956236021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2165236 (or 2165233 counting only the distinct ones).

The product of its (nonzero) digits is 4665600, while the sum is 54.

The spelling of 1685956236021 in words is "one trillion, six hundred eighty-five billion, nine hundred fifty-six million, two hundred thirty-six thousand, twenty-one".