99507521 has 2 divisors, whose sum is σ = 99507522. Its totient is φ = 99507520.

The previous prime is 99507487. The next prime is 99507557. The reversal of 99507521 is 12570599.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98803600 + 703921 = 9940^2 + 839^2 .

It is a cyclic number.

It is not a de Polignac number, because 99507521 - 2²⁶ = 32398657 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (99507581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49753760 + 49753761.

It is an arithmetic number, because the mean of its divisors is an integer number (49753761).

Almost surely, 2^99507521 is an apocalyptic number.

It is an amenable number.

99507521 is a deficient number, since it is larger than the sum of its proper divisors (1).

99507521 is an equidigital number, since it uses as much as digits as its factorization.

99507521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 28350, while the sum is 38.

The square root of 99507521 is about 9975.3456581715. The cubic root of 99507521 is about 463.3956674183.

It can be divided in two parts, 9950 and 7521, that added together give a palindrome (17471).

The spelling of 99507521 in words is "ninety-nine million, five hundred seven thousand, five hundred twenty-one".