181949391444 has 24 divisors (see below), whose sum is σ = 424555562368. Its totient is φ = 60648799680.

The previous prime is 181949391439. The next prime is 181949391451. The reversal of 181949391444 is 444193949181.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 1189029 + ... + 1333299.

Almost surely, 2^181949391444 is an apocalyptic number.

It is an amenable number.

181949391444 is an abundant number, since it is smaller than the sum of its proper divisors (242606170924).

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

181949391444 is a wasteful number, since it uses less digits than its factorization.

181949391444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249375 (or 249373 counting only the distinct ones).

The product of its digits is 4478976, while the sum is 57.

The spelling of 181949391444 in words is "one hundred eighty-one billion, nine hundred forty-nine million, three hundred ninety-one thousand, four hundred forty-four".