13218171661020 has 48 divisors (see below), whose sum is σ = 37011075621408. Its totient is φ = 3524827207680.

The previous prime is 13218171660971. The next prime is 13218171661021. The reversal of 13218171661020 is 2016617181231.

It is a self number, because there is not a number n which added to its sum of digits gives 13218171661020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13218171661021) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13884132 + ... + 14805588.

It is an arithmetic number, because the mean of its divisors is an integer number (771064075446).

Almost surely, 2^{13218171661020} is an apocalyptic number.

13218171661020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13218171661020 is an abundant number, since it is smaller than the sum of its proper divisors (23792903960388).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13218171661020 is a wasteful number, since it uses less digits than its factorization.

13218171661020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1160550 (or 1160548 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 39.

The spelling of 13218171661020 in words is "thirteen trillion, two hundred eighteen billion, one hundred seventy-one million, six hundred sixty-one thousand, twenty".