7998521 has 2 divisors, whose sum is σ = 7998522. Its totient is φ = 7998520.

The previous prime is 7998511. The next prime is 7998533. The reversal of 7998521 is 1258997.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4141225 + 3857296 = 2035^2 + 1964^2 .

It is a cyclic number.

It is not a de Polignac number, because 7998521 - 2¹⁴ = 7982137 is a prime.

It is not a weakly prime, because it can be changed into another prime (7998511) 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 as a sum of consecutive naturals, namely, 3999260 + 3999261.

It is an arithmetic number, because the mean of its divisors is an integer number (3999261).

Almost surely, 2^7998521 is an apocalyptic number.

It is an amenable number.

7998521 is a deficient number, since it is larger than the sum of its proper divisors (1).

7998521 is an equidigital number, since it uses as much as digits as its factorization.

7998521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 41.

The square root of 7998521 is about 2828.1656599287. The cubic root of 7998521 is about 199.9876742404.

The spelling of 7998521 in words is "seven million, nine hundred ninety-eight thousand, five hundred twenty-one".