21515454163289 has 2 divisors, whose sum is σ = 21515454163290. Its totient is φ = 21515454163288.

The previous prime is 21515454163267. The next prime is 21515454163309. The reversal of 21515454163289 is 98236145451512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12033211707664 + 9482242455625 = 3468892^2 + 3079325^2 .

It is a cyclic number.

It is not a de Polignac number, because 21515454163289 - 2⁸ = 21515454163033 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21515454363289) 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, 10757727081644 + 10757727081645.

It is an arithmetic number, because the mean of its divisors is an integer number (10757727081645).

Almost surely, 2^{21515454163289} is an apocalyptic number.

It is an amenable number.

21515454163289 is a deficient number, since it is larger than the sum of its proper divisors (1).

21515454163289 is an equidigital number, since it uses as much as digits as its factorization.

21515454163289 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10368000, while the sum is 56.

The spelling of 21515454163289 in words is "twenty-one trillion, five hundred fifteen billion, four hundred fifty-four million, one hundred sixty-three thousand, two hundred eighty-nine".