7381818 has 24 divisors (see below), whose sum is σ = 16049748. Its totient is φ = 2452032.

The previous prime is 7381789. The next prime is 7381819. The reversal of 7381818 is 8181837.

It can be written as a sum of positive squares in 2 ways, for example, as 6335289 + 1046529 = 2517^2 + 1023^2 .

It is an Ulam number.

7381818 is a modest number, since divided by 1818 gives 738 as remainder.

It is not an unprimeable number, because it can be changed into a prime (7381819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6630 + ... + 7662.

Almost surely, 2^7381818 is an apocalyptic number.

7381818 is an abundant number, since it is smaller than the sum of its proper divisors (8667930).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7381818 is a wasteful number, since it uses less digits than its factorization.

7381818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1438 (or 1435 counting only the distinct ones).

The product of its digits is 10752, while the sum is 36.

The square root of 7381818 is about 2716.9501283608. The cubic root of 7381818 is about 194.7097852558.

It can be divided in two parts, 738 and 1818, that added together give a triangular number (2556 = T₇₁).

The spelling of 7381818 in words is "seven million, three hundred eighty-one thousand, eight hundred eighteen".