21034857272017 has 2 divisors, whose sum is σ = 21034857272018. Its totient is φ = 21034857272016.

The previous prime is 21034857271781. The next prime is 21034857272063. The reversal of 21034857272017 is 71027275843012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19166848976016 + 1868008296001 = 4377996^2 + 1366751^2 .

It is a cyclic number.

It is not a de Polignac number, because 21034857272017 - 2²³ = 21034848883409 is a prime.

It is not a weakly prime, because it can be changed into another prime (21034857572017) 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, 10517428636008 + 10517428636009.

It is an arithmetic number, because the mean of its divisors is an integer number (10517428636009).

Almost surely, 2^{21034857272017} is an apocalyptic number.

It is an amenable number.

21034857272017 is a deficient number, since it is larger than the sum of its proper divisors (1).

21034857272017 is an equidigital number, since it uses as much as digits as its factorization.

21034857272017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1317120, while the sum is 49.

The spelling of 21034857272017 in words is "twenty-one trillion, thirty-four billion, eight hundred fifty-seven million, two hundred seventy-two thousand, seventeen".