7991818 has 12 divisors (see below), whose sum is σ = 12653010. Its totient is φ = 3785256.

The previous prime is 7991803. The next prime is 7991839. The reversal of 7991818 is 8181997.

It can be written as a sum of positive squares in only one way, i.e., 7800849 + 190969 = 2793^2 + 437^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4813 + ... + 6256.

Almost surely, 2^7991818 is an apocalyptic number.

7991818 is a deficient number, since it is larger than the sum of its proper divisors (4661192).

7991818 is a wasteful number, since it uses less digits than its factorization.

7991818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11109 (or 11090 counting only the distinct ones).

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

The square root of 7991818 is about 2826.9803678130. The cubic root of 7991818 is about 199.9317934086.

The spelling of 7991818 in words is "seven million, nine hundred ninety-one thousand, eight hundred eighteen".