6691961699 has 2 divisors, whose sum is σ = 6691961700. Its totient is φ = 6691961698.

The previous prime is 6691961693. The next prime is 6691961701. The reversal of 6691961699 is 9961691966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6691961699 - 2¹⁶ = 6691896163 is a prime.

Together with 6691961701, it forms a pair of twin primes.

It is a Chen prime.

6691961699 is a strobogrammatic number because it is the same when read upside-down.

It is not a weakly prime, because it can be changed into another prime (6691961693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3345980849 + 3345980850.

It is an arithmetic number, because the mean of its divisors is an integer number (3345980850).

Almost surely, 2^6691961699 is an apocalyptic number.

6691961699 is a deficient number, since it is larger than the sum of its proper divisors (1).

6691961699 is an equidigital number, since it uses as much as digits as its factorization.

6691961699 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8503056, while the sum is 62.

The square root of 6691961699 is about 81804.4112441377. The cubic root of 6691961699 is about 1884.4494072136.

The spelling of 6691961699 in words is "six billion, six hundred ninety-one million, nine hundred sixty-one thousand, six hundred ninety-nine".