13004991 has 6 divisors (see below), whose sum is σ = 18785000. Its totient is φ = 8669988.

The previous prime is 13004989. The next prime is 13004993. The reversal of 13004991 is 19940031.

13004991 = 464² + 465² + ... + 517².

It is an interprime number because it is at equal distance from previous prime (13004989) and next prime (13004993).

It is not a de Polignac number, because 13004991 - 2¹ = 13004989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13004993) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 722491 + ... + 722508.

Almost surely, 2^13004991 is an apocalyptic number.

13004991 is a deficient number, since it is larger than the sum of its proper divisors (5780009).

13004991 is a wasteful number, since it uses less digits than its factorization.

13004991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1445005 (or 1445002 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 13004991 is about 3606.2433362157. The cubic root of 13004991 is about 235.1635559770.

The spelling of 13004991 in words is "thirteen million, four thousand, nine hundred ninety-one".