7991605 has 12 divisors (see below), whose sum is σ = 9791460. Its totient is φ = 6261632.

The previous prime is 7991591. The next prime is 7991623. The reversal of 7991605 is 5061997.

It can be written as a sum of positive squares in 6 ways, for example, as 5329 + 7986276 = 73^2 + 2826^2 .

It is not a de Polignac number, because 7991605 - 2⁵ = 7991573 is a prime.

7991605 is a lucky number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13761 + ... + 14329.

It is an arithmetic number, because the mean of its divisors is an integer number (815955).

Almost surely, 2^7991605 is an apocalyptic number.

It is an amenable number.

7991605 is a deficient number, since it is larger than the sum of its proper divisors (1799855).

7991605 is an equidigital number, since it uses as much as digits as its factorization.

7991605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680 (or 627 counting only the distinct ones).

The product of its (nonzero) digits is 17010, while the sum is 37.

The square root of 7991605 is about 2826.9426948561. The cubic root of 7991605 is about 199.9300171815.

The spelling of 7991605 in words is "seven million, nine hundred ninety-one thousand, six hundred five".