7518821 has 2 divisors, whose sum is σ = 7518822. Its totient is φ = 7518820.

The previous prime is 7518803. The next prime is 7518853. The reversal of 7518821 is 1288157.

It is a happy number.

It is an a-pointer prime, because the next prime (7518853) can be obtained adding 7518821 to its sum of digits (32).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4456321 + 3062500 = 2111^2 + 1750^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7518821 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7518871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3759410 + 3759411.

It is an arithmetic number, because the mean of its divisors is an integer number (3759411).

Almost surely, 2^7518821 is an apocalyptic number.

It is an amenable number.

7518821 is a deficient number, since it is larger than the sum of its proper divisors (1).

7518821 is an equidigital number, since it uses as much as digits as its factorization.

7518821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 32.

The square root of 7518821 is about 2742.0468632027. The cubic root of 7518821 is about 195.9069824489.

The spelling of 7518821 in words is "seven million, five hundred eighteen thousand, eight hundred twenty-one".