7989181 has 4 divisors (see below), whose sum is σ = 8264700. Its totient is φ = 7713664.

The previous prime is 7989173. The next prime is 7989187. The reversal of 7989181 is 1819897.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1819897 = 317 ⋅5741.

It can be written as a sum of positive squares in 2 ways, for example, as 2277081 + 5712100 = 1509^2 + 2390^2 .

It is a cyclic number.

It is not a de Polignac number, because 7989181 - 2³ = 7989173 is a prime.

It is a super-2 number, since 2×7989181² = 127654026101522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7989187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 137716 + ... + 137773.

It is an arithmetic number, because the mean of its divisors is an integer number (2066175).

Almost surely, 2^7989181 is an apocalyptic number.

It is an amenable number.

7989181 is a deficient number, since it is larger than the sum of its proper divisors (275519).

7989181 is a wasteful number, since it uses less digits than its factorization.

7989181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 275518.

The product of its digits is 36288, while the sum is 43.

The square root of 7989181 is about 2826.5139306220. The cubic root of 7989181 is about 199.9098009935.

The spelling of 7989181 in words is "seven million, nine hundred eighty-nine thousand, one hundred eighty-one".