17944972121 has 4 divisors (see below), whose sum is σ = 18025443072. Its totient is φ = 17864501172.

The previous prime is 17944972109. The next prime is 17944972169. The reversal of 17944972121 is 12127944971.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 17944972121 - 2¹⁴ = 17944955737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (17944972181) 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 in 3 ways as a sum of consecutive naturals, for example, 40235141 + ... + 40235586.

It is an arithmetic number, because the mean of its divisors is an integer number (4506360768).

Almost surely, 2^17944972121 is an apocalyptic number.

It is an amenable number.

17944972121 is a deficient number, since it is larger than the sum of its proper divisors (80470951).

17944972121 is an equidigital number, since it uses as much as digits as its factorization.

17944972121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80470950.

The product of its digits is 254016, while the sum is 47.

The spelling of 17944972121 in words is "seventeen billion, nine hundred forty-four million, nine hundred seventy-two thousand, one hundred twenty-one".