181386881 has 8 divisors (see below), whose sum is σ = 195515880. Its totient is φ = 167283072.

The previous prime is 181386871. The next prime is 181386893. The reversal of 181386881 is 188683181.

It can be written as a sum of positive squares in 4 ways, for example, as 29604481 + 151782400 = 5441^2 + 12320^2 .

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 181386881 - 2¹⁰ = 181385857 is a prime.

It is a super-2 number, since 2×181386881² = 65802401197816322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (181386871) 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, 10301 + ... + 21653.

It is an arithmetic number, because the mean of its divisors is an integer number (24439485).

Almost surely, 2^181386881 is an apocalyptic number.

It is an amenable number.

181386881 is a deficient number, since it is larger than the sum of its proper divisors (14128999).

181386881 is a wasteful number, since it uses less digits than its factorization.

181386881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12595.

The product of its digits is 73728, while the sum is 44.

The square root of 181386881 is about 13467.9946911186. The cubic root of 181386881 is about 566.0680255115.

The spelling of 181386881 in words is "one hundred eighty-one million, three hundred eighty-six thousand, eight hundred eighty-one".