15523123122121 has 2 divisors, whose sum is σ = 15523123122122. Its totient is φ = 15523123122120.

The previous prime is 15523123122097. The next prime is 15523123122137. The reversal of 15523123122121 is 12122132132551.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13501479918096 + 2021643204025 = 3674436^2 + 1421845^2 .

It is a cyclic number.

It is not a de Polignac number, because 15523123122121 - 2³⁷ = 15385684168649 is a prime.

It is not a weakly prime, because it can be changed into another prime (15523123122151) 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, 7761561561060 + 7761561561061.

It is an arithmetic number, because the mean of its divisors is an integer number (7761561561061).

Almost surely, 2^{15523123122121} is an apocalyptic number.

It is an amenable number.

15523123122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

15523123122121 is an equidigital number, since it uses as much as digits as its factorization.

15523123122121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7200, while the sum is 31.

Adding to 15523123122121 its reverse (12122132132551), we get a palindrome (27645255254672).

The spelling of 15523123122121 in words is "fifteen trillion, five hundred twenty-three billion, one hundred twenty-three million, one hundred twenty-two thousand, one hundred twenty-one".