6991222387 has 6 divisors (see below), whose sum is σ = 7378548108. Its totient is φ = 6623262972.

The previous prime is 6991222351. The next prime is 6991222397. The reversal of 6991222387 is 7832221996.

It is not a de Polignac number, because 6991222387 - 2¹¹ = 6991220339 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6991222387.

It is not an unprimeable number, because it can be changed into a prime (6991222327) 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 5 ways as a sum of consecutive naturals, for example, 9682773 + ... + 9683494.

It is an arithmetic number, because the mean of its divisors is an integer number (1229758018).

Almost surely, 2^6991222387 is an apocalyptic number.

6991222387 is a deficient number, since it is larger than the sum of its proper divisors (387325721).

6991222387 is a wasteful number, since it uses less digits than its factorization.

6991222387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19366305 (or 19366286 counting only the distinct ones).

The product of its digits is 653184, while the sum is 49.

The square root of 6991222387 is about 83613.5299278771. The cubic root of 6991222387 is about 1912.1312783520.

The spelling of 6991222387 in words is "six billion, nine hundred ninety-one million, two hundred twenty-two thousand, three hundred eighty-seven".