90005405561 has 2 divisors, whose sum is σ = 90005405562. Its totient is φ = 90005405560.

The previous prime is 90005405551. The next prime is 90005405593. The reversal of 90005405561 is 16550450009.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 49843241536 + 40162164025 = 223256^2 + 200405^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-90005405561 is a prime.

It is not a weakly prime, because it can be changed into another prime (90005405521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45002702780 + 45002702781.

It is an arithmetic number, because the mean of its divisors is an integer number (45002702781).

Almost surely, 2^90005405561 is an apocalyptic number.

It is an amenable number.

90005405561 is a deficient number, since it is larger than the sum of its proper divisors (1).

90005405561 is an equidigital number, since it uses as much as digits as its factorization.

90005405561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 27000, while the sum is 35.

The spelling of 90005405561 in words is "ninety billion, five million, four hundred five thousand, five hundred sixty-one".