6991471 has 8 divisors (see below), whose sum is σ = 7725024. Its totient is φ = 6293760.

The previous prime is 6991463. The next prime is 6991493. The reversal of 6991471 is 1741996.

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 6991471 - 2³ = 6991463 is a prime.

It is a super-3 number, since 3×6991471³ (a number of 22 digits) contains 333 as substring.

It is a Duffinian number.

6991471 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 6991471.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991571) 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, 8550 + ... + 9331.

It is an arithmetic number, because the mean of its divisors is an integer number (965628).

Almost surely, 2^6991471 is an apocalyptic number.

6991471 is a deficient number, since it is larger than the sum of its proper divisors (733553).

6991471 is a wasteful number, since it uses less digits than its factorization.

6991471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17921.

The product of its digits is 13608, while the sum is 37.

The square root of 6991471 is about 2644.1389902953. The cubic root of 6991471 is about 191.2153943681.

The spelling of 6991471 in words is "six million, nine hundred ninety-one thousand, four hundred seventy-one".