7685521 has 2 divisors, whose sum is σ = 7685522. Its totient is φ = 7685520.

The previous prime is 7685501. The next prime is 7685527. The reversal of 7685521 is 1255867.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6150400 + 1535121 = 2480^2 + 1239^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7685521 is a prime.

It is an Ulam number.

7685521 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (7685527) 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, 3842760 + 3842761.

It is an arithmetic number, because the mean of its divisors is an integer number (3842761).

Almost surely, 2^7685521 is an apocalyptic number.

It is an amenable number.

7685521 is a deficient number, since it is larger than the sum of its proper divisors (1).

7685521 is an equidigital number, since it uses as much as digits as its factorization.

7685521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16800, while the sum is 34.

The square root of 7685521 is about 2772.2772227900. The cubic root of 7685521 is about 197.3442322500.

The spelling of 7685521 in words is "seven million, six hundred eighty-five thousand, five hundred twenty-one".