6991439213 has 16 divisors (see below), whose sum is σ = 7777720320. Its totient is φ = 6231178800.

The previous prime is 6991439179. The next prime is 6991439243. The reversal of 6991439213 is 3129341996.

It is a happy number.

It is not a de Polignac number, because 6991439213 - 2¹² = 6991435117 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991439243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 133028 + ... + 177986.

It is an arithmetic number, because the mean of its divisors is an integer number (486107520).

Almost surely, 2^6991439213 is an apocalyptic number.

It is an amenable number.

6991439213 is a deficient number, since it is larger than the sum of its proper divisors (786281107).

6991439213 is a wasteful number, since it uses less digits than its factorization.

6991439213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45248.

The product of its digits is 314928, while the sum is 47.

The square root of 6991439213 is about 83614.8265142014. The cubic root of 6991439213 is about 1912.1510457817.

The spelling of 6991439213 in words is "six billion, nine hundred ninety-one million, four hundred thirty-nine thousand, two hundred thirteen".