6691359649 has 4 divisors (see below), whose sum is σ = 7206079636. Its totient is φ = 6176639664.

The previous prime is 6691359643. The next prime is 6691359659. The reversal of 6691359649 is 9469531966.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1854852624 + 4836507025 = 43068^2 + 69545^2 .

It is a de Polignac number, because none of the positive numbers 2^k-6691359649 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 6691359593 and 6691359602.

It is not an unprimeable number, because it can be changed into a prime (6691359643) 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, 257359974 + ... + 257359999.

It is an arithmetic number, because the mean of its divisors is an integer number (1801519909).

Almost surely, 2^6691359649 is an apocalyptic number.

It is an amenable number.

6691359649 is a deficient number, since it is larger than the sum of its proper divisors (514719987).

6691359649 is a wasteful number, since it uses less digits than its factorization.

6691359649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 514719986.

The product of its digits is 9447840, while the sum is 58.

The square root of 6691359649 is about 81800.7313475864. The cubic root of 6691359649 is about 1884.3928933023.

The spelling of 6691359649 in words is "six billion, six hundred ninety-one million, three hundred fifty-nine thousand, six hundred forty-nine".