2154889017817 has 2 divisors, whose sum is σ = 2154889017818. Its totient is φ = 2154889017816.

The previous prime is 2154889017779. The next prime is 2154889017833. The reversal of 2154889017817 is 7187109884512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2139971082496 + 14917935321 = 1462864^2 + 122139^2 .

It is a cyclic number.

It is not a de Polignac number, because 2154889017817 - 2¹⁵ = 2154888985049 is a prime.

It is not a weakly prime, because it can be changed into another prime (2154889027817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077444508908 + 1077444508909.

It is an arithmetic number, because the mean of its divisors is an integer number (1077444508909).

Almost surely, 2^{2154889017817} is an apocalyptic number.

It is an amenable number.

2154889017817 is a deficient number, since it is larger than the sum of its proper divisors (1).

2154889017817 is an equidigital number, since it uses as much as digits as its factorization.

2154889017817 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9031680, while the sum is 61.

The spelling of 2154889017817 in words is "two trillion, one hundred fifty-four billion, eight hundred eighty-nine million, seventeen thousand, eight hundred seventeen".