6858391663 has 4 divisors (see below), whose sum is σ = 6860630920. Its totient is φ = 6856152408.

The previous prime is 6858391649. The next prime is 6858391667. The reversal of 6858391663 is 3661938586.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6858391663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6858391667) 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, 1115028 + ... + 1121161.

It is an arithmetic number, because the mean of its divisors is an integer number (1715157730).

Almost surely, 2^6858391663 is an apocalyptic number.

6858391663 is a deficient number, since it is larger than the sum of its proper divisors (2239257).

6858391663 is a wasteful number, since it uses less digits than its factorization.

6858391663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2239256.

The product of its digits is 5598720, while the sum is 55.

The square root of 6858391663 is about 82815.4071595377. The cubic root of 6858391663 is about 1899.9438268711.

The spelling of 6858391663 in words is "six billion, eight hundred fifty-eight million, three hundred ninety-one thousand, six hundred sixty-three".