7564535521 has 2 divisors, whose sum is σ = 7564535522. Its totient is φ = 7564535520.

The previous prime is 7564535513. The next prime is 7564535549. The reversal of 7564535521 is 1255354657.

7564535521 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6159110400 + 1405425121 = 78480^2 + 37489^2 .

It is a cyclic number.

It is not a de Polignac number, because 7564535521 - 2³ = 7564535513 is a prime.

It is not a weakly prime, because it can be changed into another prime (7564535501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3782267760 + 3782267761.

It is an arithmetic number, because the mean of its divisors is an integer number (3782267761).

Almost surely, 2^7564535521 is an apocalyptic number.

It is an amenable number.

7564535521 is a deficient number, since it is larger than the sum of its proper divisors (1).

7564535521 is an equidigital number, since it uses as much as digits as its factorization.

7564535521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 630000, while the sum is 43.

The square root of 7564535521 is about 86974.3382900957. The cubic root of 7564535521 is about 1963.0321941567.

The spelling of 7564535521 in words is "seven billion, five hundred sixty-four million, five hundred thirty-five thousand, five hundred twenty-one".