21231216029017 has 2 divisors, whose sum is σ = 21231216029018. Its totient is φ = 21231216029016.

The previous prime is 21231216028937. The next prime is 21231216029029. The reversal of 21231216029017 is 71092061213212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19294723915776 + 1936492113241 = 4392576^2 + 1391579^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231216029017 is a prime.

It is not a weakly prime, because it can be changed into another prime (21231216069017) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615608014508 + 10615608014509.

It is an arithmetic number, because the mean of its divisors is an integer number (10615608014509).

Almost surely, 2^{21231216029017} is an apocalyptic number.

It is an amenable number.

21231216029017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231216029017 is an equidigital number, since it uses as much as digits as its factorization.

21231216029017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 18144, while the sum is 37.

The spelling of 21231216029017 in words is "twenty-one trillion, two hundred thirty-one billion, two hundred sixteen million, twenty-nine thousand, seventeen".