999999901181 has 2 divisors, whose sum is σ = 999999901182. Its totient is φ = 999999901180.

The previous prime is 999999901097. The next prime is 999999901249. The reversal of 999999901181 is 181109999999.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 902443000900 + 97556900281 = 949970^2 + 312341^2 .

It is a cyclic number.

It is not a de Polignac number, because 999999901181 - 2³⁸ = 725121994237 is a prime.

It is a super-2 number, since 2×999999901181² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 999999901099 and 999999901108.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999999901981) 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, 499999950590 + 499999950591.

It is an arithmetic number, because the mean of its divisors is an integer number (499999950591).

Almost surely, 2^999999901181 is an apocalyptic number.

It is an amenable number.

999999901181 is a deficient number, since it is larger than the sum of its proper divisors (1).

999999901181 is an equidigital number, since it uses as much as digits as its factorization.

999999901181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38263752, while the sum is 74.

The spelling of 999999901181 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, nine hundred one thousand, one hundred eighty-one".