99765521 has 2 divisors, whose sum is σ = 99765522. Its totient is φ = 99765520.

The previous prime is 99765509. The next prime is 99765541. The reversal of 99765521 is 12556799.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98227921 + 1537600 = 9911^2 + 1240^2 .

It is an emirp because it is prime and its reverse (12556799) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99765521 is a prime.

It is a super-3 number, since 3×99765521³ (a number of 25 digits) contains 333 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is not a weakly prime, because it can be changed into another prime (99765541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49882760 + 49882761.

It is an arithmetic number, because the mean of its divisors is an integer number (49882761).

Almost surely, 2^99765521 is an apocalyptic number.

It is an amenable number.

99765521 is a deficient number, since it is larger than the sum of its proper divisors (1).

99765521 is an equidigital number, since it uses as much as digits as its factorization.

99765521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 170100, while the sum is 44.

The square root of 99765521 is about 9988.2691693806. The cubic root of 99765521 is about 463.7958144037.

The spelling of 99765521 in words is "ninety-nine million, seven hundred sixty-five thousand, five hundred twenty-one".