6991312 has 10 divisors (see below), whose sum is σ = 13545698. Its totient is φ = 3495648.

The previous prime is 6991289. The next prime is 6991319. The reversal of 6991312 is 2131996.

It can be written as a sum of positive squares in only one way, i.e., 6990736 + 576 = 2644^2 + 24^2 .

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6991319) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 218463 + ... + 218494.

Almost surely, 2^6991312 is an apocalyptic number.

It is an amenable number.

6991312 is a deficient number, since it is larger than the sum of its proper divisors (6554386).

6991312 is a wasteful number, since it uses less digits than its factorization.

6991312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 436965 (or 436959 counting only the distinct ones).

The product of its digits is 2916, while the sum is 31.

The square root of 6991312 is about 2644.1089236263. The cubic root of 6991312 is about 191.2139448172.

The spelling of 6991312 in words is "six million, nine hundred ninety-one thousand, three hundred twelve".