7991289 has 6 divisors (see below), whose sum is σ = 11542986. Its totient is φ = 5327520.

The previous prime is 7991257. The next prime is 7991303. The reversal of 7991289 is 9821997.

It can be written as a sum of positive squares in only one way, i.e., 5405625 + 2585664 = 2325^2 + 1608^2 .

It is not a de Polignac number, because 7991289 - 2⁵ = 7991257 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7991209) 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, 443952 + ... + 443969.

It is an arithmetic number, because the mean of its divisors is an integer number (1923831).

Almost surely, 2^7991289 is an apocalyptic number.

It is an amenable number.

7991289 is a deficient number, since it is larger than the sum of its proper divisors (3551697).

7991289 is a wasteful number, since it uses less digits than its factorization.

7991289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 887927 (or 887924 counting only the distinct ones).

The product of its digits is 81648, while the sum is 45.

The square root of 7991289 is about 2826.8868035349. The cubic root of 7991289 is about 199.9273819696.

The spelling of 7991289 in words is "seven million, nine hundred ninety-one thousand, two hundred eighty-nine".