11990159981 has 2 divisors, whose sum is σ = 11990159982. Its totient is φ = 11990159980.

The previous prime is 11990159957. The next prime is 11990160001. The reversal of 11990159981 is 18995109911.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9558190756 + 2431969225 = 97766^2 + 49315^2 .

It is a cyclic number.

It is not a de Polignac number, because 11990159981 - 2³⁰ = 10916418157 is a prime.

It is a super-2 number, since 2×11990159981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11990159911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5995079990 + 5995079991.

It is an arithmetic number, because the mean of its divisors is an integer number (5995079991).

Almost surely, 2^11990159981 is an apocalyptic number.

It is an amenable number.

11990159981 is a deficient number, since it is larger than the sum of its proper divisors (1).

11990159981 is an equidigital number, since it uses as much as digits as its factorization.

11990159981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 262440, while the sum is 53.

The spelling of 11990159981 in words is "eleven billion, nine hundred ninety million, one hundred fifty-nine thousand, nine hundred eighty-one".