6991172915 has 8 divisors (see below), whose sum is σ = 8395552800. Its totient is φ = 5588841472.

The previous prime is 6991172899. The next prime is 6991172927. The reversal of 6991172915 is 5192711996.

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 6991172915 - 2⁴ = 6991172899 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 504590 + ... + 518259.

It is an arithmetic number, because the mean of its divisors is an integer number (1049444100).

Almost surely, 2^6991172915 is an apocalyptic number.

6991172915 is a deficient number, since it is larger than the sum of its proper divisors (1404379885).

6991172915 is a wasteful number, since it uses less digits than its factorization.

6991172915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1024221.

The product of its digits is 306180, while the sum is 50.

The square root of 6991172915 is about 83613.2340900650. The cubic root of 6991172915 is about 1912.1267680687.

The spelling of 6991172915 in words is "six billion, nine hundred ninety-one million, one hundred seventy-two thousand, nine hundred fifteen".