13661166422021 has 4 divisors (see below), whose sum is σ = 13661359936044. Its totient is φ = 13660972908000.

The previous prime is 13661166422011. The next prime is 13661166422053. The reversal of 13661166422021 is 12022466116631.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9749319312100 + 3911847109921 = 3122390^2 + 1977839^2 .

It is a cyclic number.

It is not a de Polignac number, because 13661166422021 - 2¹⁸ = 13661166159877 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13661166422021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13661166422011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96651080 + ... + 96792321.

It is an arithmetic number, because the mean of its divisors is an integer number (3415339984011).

Almost surely, 2^{13661166422021} is an apocalyptic number.

It is an amenable number.

13661166422021 is a deficient number, since it is larger than the sum of its proper divisors (193514023).

13661166422021 is an equidigital number, since it uses as much as digits as its factorization.

13661166422021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193514022.

The product of its (nonzero) digits is 124416, while the sum is 41.

The spelling of 13661166422021 in words is "thirteen trillion, six hundred sixty-one billion, one hundred sixty-six million, four hundred twenty-two thousand, twenty-one".