15511797121 has 2 divisors, whose sum is σ = 15511797122. Its totient is φ = 15511797120.

The previous prime is 15511797113. The next prime is 15511797151. The reversal of 15511797121 is 12179711551.

15511797121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12082406400 + 3429390721 = 109920^2 + 58561^2 .

It is a cyclic number.

It is not a de Polignac number, because 15511797121 - 2³ = 15511797113 is a prime.

It is not a weakly prime, because it can be changed into another prime (15511797151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7755898560 + 7755898561.

It is an arithmetic number, because the mean of its divisors is an integer number (7755898561).

Almost surely, 2^15511797121 is an apocalyptic number.

It is an amenable number.

15511797121 is a deficient number, since it is larger than the sum of its proper divisors (1).

15511797121 is an equidigital number, since it uses as much as digits as its factorization.

15511797121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22050, while the sum is 40.

The spelling of 15511797121 in words is "fifteen billion, five hundred eleven million, seven hundred ninety-seven thousand, one hundred twenty-one".