6687496891 has 2 divisors, whose sum is σ = 6687496892. Its totient is φ = 6687496890.

The previous prime is 6687496877. The next prime is 6687496927. The reversal of 6687496891 is 1986947866.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6687496891 - 2¹⁷ = 6687365819 is a prime.

It is a super-2 number, since 2×6687496891² = 89445229334269331762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (6687496811) 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 as a sum of consecutive naturals, namely, 3343748445 + 3343748446.

It is an arithmetic number, because the mean of its divisors is an integer number (3343748446).

Almost surely, 2^6687496891 is an apocalyptic number.

6687496891 is a deficient number, since it is larger than the sum of its proper divisors (1).

6687496891 is an equidigital number, since it uses as much as digits as its factorization.

6687496891 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31352832, while the sum is 64.

The square root of 6687496891 is about 81777.1171599978. The cubic root of 6687496891 is about 1884.0302188879.

The spelling of 6687496891 in words is "six billion, six hundred eighty-seven million, four hundred ninety-six thousand, eight hundred ninety-one".