181981056 has 128 divisors (see below), whose sum is σ = 521350560. Its totient is φ = 56033280.

The previous prime is 181981013. The next prime is 181981081. The reversal of 181981056 is 650189181.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 397980 + ... + 398436.

Almost surely, 2^181981056 is an apocalyptic number.

181981056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 181981056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260675280).

181981056 is an abundant number, since it is smaller than the sum of its proper divisors (339369504).

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

181981056 is a wasteful number, since it uses less digits than its factorization.

181981056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 39.

The square root of 181981056 is about 13490.0354336080. The cubic root of 181981056 is about 566.6854477435.

The spelling of 181981056 in words is "one hundred eighty-one million, nine hundred eighty-one thousand, fifty-six".