1218666961449 has 160 divisors (see below), whose sum is σ = 2211133478400. Its totient is φ = 653837184000.

The previous prime is 1218666961441. The next prime is 1218666961513. The reversal of 1218666961449 is 9441696668121.

It is a happy number.

It is not a de Polignac number, because 1218666961449 - 2³ = 1218666961441 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1218666961441) by changing a digit.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 478094827 + ... + 478097375.

It is an arithmetic number, because the mean of its divisors is an integer number (13819584240).

Almost surely, 2^{1218666961449} is an apocalyptic number.

It is an amenable number.

1218666961449 is a deficient number, since it is larger than the sum of its proper divisors (992466516951).

1218666961449 is a wasteful number, since it uses less digits than its factorization.

1218666961449 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3253 (or 3244 counting only the distinct ones).

The product of its digits is 26873856, while the sum is 63.

The spelling of 1218666961449 in words is "one trillion, two hundred eighteen billion, six hundred sixty-six million, nine hundred sixty-one thousand, four hundred forty-nine".