7218738 has 24 divisors (see below), whose sum is σ = 16181100. Its totient is φ = 2323104.

The previous prime is 7218721. The next prime is 7218749. The reversal of 7218738 is 8378127.

It can be written as a sum of positive squares in 2 ways, for example, as 6985449 + 233289 = 2643^2 + 483^2 .

It is a super-2 number, since 2×7218738² = 104220356625288, which contains 22 as substring.

It is an unprimeable number.

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, 6393 + ... + 7436.

Almost surely, 2^7218738 is an apocalyptic number.

7218738 is an abundant number, since it is smaller than the sum of its proper divisors (8962362).

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

7218738 is a wasteful number, since it uses less digits than its factorization.

7218738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13866 (or 13863 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 7218738 is about 2686.7709243626. The cubic root of 7218738 is about 193.2652442221.

The spelling of 7218738 in words is "seven million, two hundred eighteen thousand, seven hundred thirty-eight".