181744027921 has 8 divisors (see below), whose sum is σ = 183557773224. Its totient is φ = 179930563200.

The previous prime is 181744027909. The next prime is 181744027931. The reversal of 181744027921 is 129720447181.

It can be written as a sum of positive squares in 4 ways, for example, as 47073377296 + 134670650625 = 216964^2 + 366975^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 181744027921 - 2³¹ = 179596544273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181744027901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1380645 + ... + 1506541.

It is an arithmetic number, because the mean of its divisors is an integer number (22944721653).

Almost surely, 2^181744027921 is an apocalyptic number.

It is an amenable number.

181744027921 is a deficient number, since it is larger than the sum of its proper divisors (1813745303).

181744027921 is a wasteful number, since it uses less digits than its factorization.

181744027921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140291.

The product of its (nonzero) digits is 225792, while the sum is 46.

The spelling of 181744027921 in words is "one hundred eighty-one billion, seven hundred forty-four million, twenty-seven thousand, nine hundred twenty-one".