181939322881 has 8 divisors (see below), whose sum is σ = 185817613824. Its totient is φ = 178061333760.

The previous prime is 181939322801. The next prime is 181939322891. The reversal of 181939322881 is 188223939181.

It is a happy number.

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 181939322881 - 2¹¹ = 181939320833 is a prime.

It is a super-2 number, since 2×181939322881² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181939322801) 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, 1481761 + ... + 1599841.

It is an arithmetic number, because the mean of its divisors is an integer number (23227201728).

Almost surely, 2^181939322881 is an apocalyptic number.

It is an amenable number.

181939322881 is a deficient number, since it is larger than the sum of its proper divisors (3878290943).

181939322881 is a wasteful number, since it uses less digits than its factorization.

181939322881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150911.

The product of its digits is 1492992, while the sum is 55.

The spelling of 181939322881 in words is "one hundred eighty-one billion, nine hundred thirty-nine million, three hundred twenty-two thousand, eight hundred eighty-one".