15121433981 has 2 divisors, whose sum is σ = 15121433982. Its totient is φ = 15121433980.

The previous prime is 15121433941. The next prime is 15121434001. The reversal of 15121433981 is 18933412151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7970025625 + 7151408356 = 89275^2 + 84566^2 .

It is an emirp because it is prime and its reverse (18933412151) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 15121433981 - 2³⁰ = 14047692157 is a prime.

It is a super-2 number, since 2×15121433981² (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 (15121433941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7560716990 + 7560716991.

It is an arithmetic number, because the mean of its divisors is an integer number (7560716991).

Almost surely, 2^15121433981 is an apocalyptic number.

It is an amenable number.

15121433981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15121433981 is an equidigital number, since it uses as much as digits as its factorization.

15121433981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 25920, while the sum is 38.

The spelling of 15121433981 in words is "fifteen billion, one hundred twenty-one million, four hundred thirty-three thousand, nine hundred eighty-one".