6991246081 has 4 divisors (see below), whose sum is σ = 6991838932. Its totient is φ = 6990653232.

The previous prime is 6991246063. The next prime is 6991246109. The reversal of 6991246081 is 1806421996.

It is a happy number.

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 3691777600 + 3299468481 = 60760^2 + 57441^2 .

It is a cyclic number.

It is not a de Polignac number, because 6991246081 - 2⁵ = 6991246049 is a prime.

It is a super-2 number, since 2×6991246081² = 97755043530195717122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6991246181) 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, 278370 + ... + 302443.

It is an arithmetic number, because the mean of its divisors is an integer number (1747959733).

Almost surely, 2^6991246081 is an apocalyptic number.

It is an amenable number.

6991246081 is a deficient number, since it is larger than the sum of its proper divisors (592851).

6991246081 is a wasteful number, since it uses less digits than its factorization.

6991246081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 592850.

The product of its (nonzero) digits is 186624, while the sum is 46.

The square root of 6991246081 is about 83613.6716153525. The cubic root of 6991246081 is about 1912.1334384887.

The spelling of 6991246081 in words is "six billion, nine hundred ninety-one million, two hundred forty-six thousand, eighty-one".