7981805 has 32 divisors (see below), whose sum is σ = 11370240. Its totient is φ = 5322240.

The previous prime is 7981801. The next prime is 7981807. The reversal of 7981805 is 5081897.

7981805 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 7981805 - 2² = 7981801 is a prime.

It is a super-2 number, since 2×7981805² = 127418422116050, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7981801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28265 + ... + 28545.

It is an arithmetic number, because the mean of its divisors is an integer number (355320).

Almost surely, 2^7981805 is an apocalyptic number.

It is an amenable number.

7981805 is a deficient number, since it is larger than the sum of its proper divisors (3388435).

7981805 is a wasteful number, since it uses less digits than its factorization.

7981805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 341.

The product of its (nonzero) digits is 20160, while the sum is 38.

The square root of 7981805 is about 2825.2088418381. The cubic root of 7981805 is about 199.8482599038.

The spelling of 7981805 in words is "seven million, nine hundred eighty-one thousand, eight hundred five".