7991000 has 64 divisors (see below), whose sum is σ = 19150560. Its totient is φ = 3120000.

The previous prime is 7990999. The next prime is 7991017. The reversal of 7991000 is 1997.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60935 + ... + 61065.

Almost surely, 2^7991000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7991000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9575280).

7991000 is an abundant number, since it is smaller than the sum of its proper divisors (11159560).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7991000 is a wasteful number, since it uses less digits than its factorization.

7991000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 213 (or 199 counting only the distinct ones).

The product of its (nonzero) digits is 567, while the sum is 26.

The square root of 7991000 is about 2826.8356867706. The cubic root of 7991000 is about 199.9249718574.

Adding to 7991000 its reverse (1997), we get a palindrome (7992997).

The spelling of 7991000 in words is "seven million, nine hundred ninety-one thousand".