99531444581 has 2 divisors, whose sum is σ = 99531444582. Its totient is φ = 99531444580.

The previous prime is 99531444503. The next prime is 99531444673. The reversal of 99531444581 is 18544413599.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99108484225 + 422960356 = 314815^2 + 20566^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99531444581 is a prime.

It is a super-2 number, since 2×99531444581² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99531449581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49765722290 + 49765722291.

It is an arithmetic number, because the mean of its divisors is an integer number (49765722291).

Almost surely, 2^99531444581 is an apocalyptic number.

It is an amenable number.

99531444581 is a deficient number, since it is larger than the sum of its proper divisors (1).

99531444581 is an equidigital number, since it uses as much as digits as its factorization.

99531444581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3110400, while the sum is 53.

The spelling of 99531444581 in words is "ninety-nine billion, five hundred thirty-one million, four hundred forty-four thousand, five hundred eighty-one".