1234555666789 has 2 divisors, whose sum is σ = 1234555666790. Its totient is φ = 1234555666788.

The previous prime is 1234555666777. The next prime is 1234555666831. The reversal of 1234555666789 is 9876665554321.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1210842746689 + 23712920100 = 1100383^2 + 153990^2 .

It is a cyclic number.

It is not a de Polignac number, because 1234555666789 - 2¹³ = 1234555658597 is a prime.

It is a plaindrome in base 10.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1234555666739) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 617277833394 + 617277833395.

It is an arithmetic number, because the mean of its divisors is an integer number (617277833395).

Almost surely, 2^{1234555666789} is an apocalyptic number.

It is an amenable number.

1234555666789 is a deficient number, since it is larger than the sum of its proper divisors (1).

1234555666789 is an equidigital number, since it uses as much as digits as its factorization.

1234555666789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592000, while the sum is 67.

The spelling of 1234555666789 in words is "one trillion, two hundred thirty-four billion, five hundred fifty-five million, six hundred sixty-six thousand, seven hundred eighty-nine".