8815621 has 2 divisors, whose sum is σ = 8815622. Its totient is φ = 8815620.

The previous prime is 8815613. The next prime is 8815637. The reversal of 8815621 is 1265188.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5013121 + 3802500 = 2239^2 + 1950^2 .

It is a cyclic number.

It is not a de Polignac number, because 8815621 - 2³ = 8815613 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8815021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4407810 + 4407811.

It is an arithmetic number, because the mean of its divisors is an integer number (4407811).

Almost surely, 2^8815621 is an apocalyptic number.

It is an amenable number.

8815621 is a deficient number, since it is larger than the sum of its proper divisors (1).

8815621 is an equidigital number, since it uses as much as digits as its factorization.

8815621 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 31.

The square root of 8815621 is about 2969.1111464544. Note that the first 4 decimals coincide. The cubic root of 8815621 is about 206.5781118466.

The spelling of 8815621 in words is "eight million, eight hundred fifteen thousand, six hundred twenty-one".