6858686021 has 4 divisors (see below), whose sum is σ = 7482202944. Its totient is φ = 6235169100.

The previous prime is 6858686017. The next prime is 6858686027. The reversal of 6858686021 is 1206868586.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 6858686021 - 2² = 6858686017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6858686027) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 311758445 + ... + 311758466.

It is an arithmetic number, because the mean of its divisors is an integer number (1870550736).

Almost surely, 2^6858686021 is an apocalyptic number.

It is an amenable number.

6858686021 is a deficient number, since it is larger than the sum of its proper divisors (623516923).

6858686021 is a wasteful number, since it uses less digits than its factorization.

6858686021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623516922.

The product of its (nonzero) digits is 1105920, while the sum is 50.

The square root of 6858686021 is about 82817.1843339292. The cubic root of 6858686021 is about 1899.9710079602.

The spelling of 6858686021 in words is "six billion, eight hundred fifty-eight million, six hundred eighty-six thousand, twenty-one".