1213166645543 has 16 divisors (see below), whose sum is σ = 1231095327360. Its totient is φ = 1195304947200.

The previous prime is 1213166645521. The next prime is 1213166645549. The reversal of 1213166645543 is 3455466613121.

It is a cyclic number.

It is not a de Polignac number, because 1213166645543 - 2²⁶ = 1213099536679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1213166645549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80223023 + ... + 80238143.

It is an arithmetic number, because the mean of its divisors is an integer number (76943457960).

Almost surely, 2^{1213166645543} is an apocalyptic number.

1213166645543 is a deficient number, since it is larger than the sum of its proper divisors (17928681817).

1213166645543 is a wasteful number, since it uses less digits than its factorization.

1213166645543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17258.

The product of its digits is 1555200, while the sum is 47.

The spelling of 1213166645543 in words is "one trillion, two hundred thirteen billion, one hundred sixty-six million, six hundred forty-five thousand, five hundred forty-three".