90005405521 has 2 divisors, whose sum is σ = 90005405522. Its totient is φ = 90005405520.

The previous prime is 90005405519. The next prime is 90005405527. The reversal of 90005405521 is 12550450009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80565145600 + 9440259921 = 283840^2 + 97161^2 .

It is a cyclic number.

It is not a de Polignac number, because 90005405521 - 2¹ = 90005405519 is a prime.

Together with 90005405519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (90005405527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45002702760 + 45002702761.

It is an arithmetic number, because the mean of its divisors is an integer number (45002702761).

Almost surely, 2^90005405521 is an apocalyptic number.

It is an amenable number.

90005405521 is a deficient number, since it is larger than the sum of its proper divisors (1).

90005405521 is an equidigital number, since it uses as much as digits as its factorization.

90005405521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9000, while the sum is 31.

The spelling of 90005405521 in words is "ninety billion, five million, four hundred five thousand, five hundred twenty-one".