7990 has 16 divisors (see below), whose sum is σ = 15552. Its totient is φ = 2944.

The previous prime is 7963. The next prime is 7993. The reversal of 7990 is 997.

7990 is an undulating number in base 13.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7993) by changing a digit.

7990 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 147 + ... + 193.

It is an arithmetic number, because the mean of its divisors is an integer number (972).

2⁷⁹⁹⁰ is an apocalyptic number.

7990 is a deficient number, since it is larger than the sum of its proper divisors (7562).

7990 is a wasteful number, since it uses less digits than its factorization.

7990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71.

The product of its (nonzero) digits is 567, while the sum is 25.

The square root of 7990 is about 89.3867999203. The cubic root of 7990 is about 19.9916631920.

It can be divided in two parts, 79 and 90, that added together give a square (169 = 13²).

The spelling of 7990 in words is "seven thousand, nine hundred ninety".