99321393581 has 2 divisors, whose sum is σ = 99321393582. Its totient is φ = 99321393580.

The previous prime is 99321393569. The next prime is 99321393601. The reversal of 99321393581 is 18539312399.

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., 73381392100 + 25940001481 = 270890^2 + 161059^2 .

It is an emirp because it is prime and its reverse (18539312399) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99321393581 - 2³⁰ = 98247651757 is a prime.

It is a super-2 number, since 2×99321393581² (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 (99321393541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49660696790 + 49660696791.

It is an arithmetic number, because the mean of its divisors is an integer number (49660696791).

Almost surely, 2^99321393581 is an apocalyptic number.

It is an amenable number.

99321393581 is a deficient number, since it is larger than the sum of its proper divisors (1).

99321393581 is an equidigital number, since it uses as much as digits as its factorization.

99321393581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1574640, while the sum is 53.

The spelling of 99321393581 in words is "ninety-nine billion, three hundred twenty-one million, three hundred ninety-three thousand, five hundred eighty-one".