6840021685 has 16 divisors (see below), whose sum is σ = 9401990400. Its totient is φ = 4679606016.

The previous prime is 6840021673. The next prime is 6840021697. The reversal of 6840021685 is 5861200486.

It is an interprime number because it is at equal distance from previous prime (6840021673) and next prime (6840021697).

It is a cyclic number.

It is not a de Polignac number, because 6840021685 - 2⁹ = 6840021173 is a prime.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 207220 + ... + 237949.

It is an arithmetic number, because the mean of its divisors is an integer number (587624400).

Almost surely, 2^6840021685 is an apocalyptic number.

It is an amenable number.

6840021685 is a deficient number, since it is larger than the sum of its proper divisors (2561968715).

6840021685 is a wasteful number, since it uses less digits than its factorization.

6840021685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445620.

The product of its (nonzero) digits is 92160, while the sum is 40.

The square root of 6840021685 is about 82704.4236120415. The cubic root of 6840021685 is about 1898.2459976184.

The spelling of 6840021685 in words is "six billion, eight hundred forty million, twenty-one thousand, six hundred eighty-five".