181423907329 has 6 divisors (see below), whose sum is σ = 211044137154. Its totient is φ = 155506206240.

The previous prime is 181423907303. The next prime is 181423907351. The reversal of 181423907329 is 923709324181.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 146269532304 + 35154375025 = 382452^2 + 187495^2 .

It is not a de Polignac number, because 181423907329 - 2⁵ = 181423907297 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49), and also a Moran number because the ratio is a prime number: 3702528721 = 181423907329 / (1 + 8 + 1 + 4 + 2 + 3 + 9 + 0 + 7 + 3 + 2 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181423907359) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1851264312 + ... + 1851264409.

It is an arithmetic number, because the mean of its divisors is an integer number (35174022859).

Almost surely, 2^181423907329 is an apocalyptic number.

It is an amenable number.

181423907329 is a deficient number, since it is larger than the sum of its proper divisors (29620229825).

181423907329 is an equidigital number, since it uses as much as digits as its factorization.

181423907329 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3702528735 (or 3702528728 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 49.

The spelling of 181423907329 in words is "one hundred eighty-one billion, four hundred twenty-three million, nine hundred seven thousand, three hundred twenty-nine".