6891908677 has 2 divisors, whose sum is σ = 6891908678. Its totient is φ = 6891908676.

The previous prime is 6891908663. The next prime is 6891908687. The reversal of 6891908677 is 7768091986.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6096330241 + 795578436 = 78079^2 + 28206^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6891908677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6891908687) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3445954338 + 3445954339.

It is an arithmetic number, because the mean of its divisors is an integer number (3445954339).

Almost surely, 2^6891908677 is an apocalyptic number.

It is an amenable number.

6891908677 is a deficient number, since it is larger than the sum of its proper divisors (1).

6891908677 is an equidigital number, since it uses as much as digits as its factorization.

6891908677 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9144576, while the sum is 61.

The square root of 6891908677 is about 83017.5203014400. The cubic root of 6891908677 is about 1903.0338122052.

The spelling of 6891908677 in words is "six billion, eight hundred ninety-one million, nine hundred eight thousand, six hundred seventy-seven".