218128201023449 has 2 divisors, whose sum is σ = 218128201023450. Its totient is φ = 218128201023448.

The previous prime is 218128201023437. The next prime is 218128201023451. The reversal of 218128201023449 is 944320102821812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 147912298086400 + 70215902937049 = 12161920^2 + 8379493^2 .

It is a cyclic number.

It is not a de Polignac number, because 218128201023449 - 2⁸ = 218128201023193 is a prime.

Together with 218128201023451, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (218128201023479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 109064100511724 + 109064100511725.

It is an arithmetic number, because the mean of its divisors is an integer number (109064100511725).

Almost surely, 2^{218128201023449} is an apocalyptic number.

It is an amenable number.

218128201023449 is a deficient number, since it is larger than the sum of its proper divisors (1).

218128201023449 is an equidigital number, since it uses as much as digits as its factorization.

218128201023449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 442368, while the sum is 47.

The spelling of 218128201023449 in words is "two hundred eighteen trillion, one hundred twenty-eight billion, two hundred one million, twenty-three thousand, four hundred forty-nine".