6699999749 has 2 divisors, whose sum is σ = 6699999750. Its totient is φ = 6699999748.

The previous prime is 6699999673. The next prime is 6699999769. The reversal of 6699999749 is 9479999966.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6386886724 + 313113025 = 79918^2 + 17695^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6699999749 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 6699999749.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6699999769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3349999874 + 3349999875.

It is an arithmetic number, because the mean of its divisors is an integer number (3349999875).

Almost surely, 2^6699999749 is an apocalyptic number.

It is an amenable number.

6699999749 is a deficient number, since it is larger than the sum of its proper divisors (1).

6699999749 is an equidigital number, since it uses as much as digits as its factorization.

6699999749 is an evil number, because the sum of its binary digits is even.

The product of its digits is 535692528, while the sum is 77.

The square root of 6699999749 is about 81853.5261854980. The cubic root of 6699999749 is about 1885.2036074794.

The spelling of 6699999749 in words is "six billion, six hundred ninety-nine million, nine hundred ninety-nine thousand, seven hundred forty-nine".