15105209981 has 2 divisors, whose sum is σ = 15105209982. Its totient is φ = 15105209980.

The previous prime is 15105209927. The next prime is 15105210011. The reversal of 15105209981 is 18990250151.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10127201956 + 4978008025 = 100634^2 + 70555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15105209981 is a prime.

It is a super-2 number, since 2×15105209981² (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 (15105206981) 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, 7552604990 + 7552604991.

It is an arithmetic number, because the mean of its divisors is an integer number (7552604991).

Almost surely, 2^15105209981 is an apocalyptic number.

It is an amenable number.

15105209981 is a deficient number, since it is larger than the sum of its proper divisors (1).

15105209981 is an equidigital number, since it uses as much as digits as its factorization.

15105209981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32400, while the sum is 41.

The spelling of 15105209981 in words is "fifteen billion, one hundred five million, two hundred nine thousand, nine hundred eighty-one".