6991441997 has 8 divisors (see below), whose sum is σ = 7530754560. Its totient is φ = 6471740880.

The previous prime is 6991441991. The next prime is 6991441999. The reversal of 6991441997 is 7991441996.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 6991441997 - 2²⁶ = 6924333133 is a prime.

It is a super-2 number, since 2×6991441997² = 97760522394830696018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991441991) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4902122 + ... + 4903547.

It is an arithmetic number, because the mean of its divisors is an integer number (941344320).

Almost surely, 2^6991441997 is an apocalyptic number.

It is an amenable number.

6991441997 is a deficient number, since it is larger than the sum of its proper divisors (539312563).

6991441997 is a wasteful number, since it uses less digits than its factorization.

6991441997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9805723.

The product of its digits is 4408992, while the sum is 59.

The square root of 6991441997 is about 83614.8431619650. The cubic root of 6991441997 is about 1912.1512995887.

Subtracting 6991441997 from its reverse (7991441996), we obtain a palindrome (999999999).

The spelling of 6991441997 in words is "six billion, nine hundred ninety-one million, four hundred forty-one thousand, nine hundred ninety-seven".