181440918 has 64 divisors (see below), whose sum is σ = 429408000. Its totient is φ = 56624832.

The previous prime is 181440893. The next prime is 181440971. The reversal of 181440918 is 819044181.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 90321 + ... + 92307.

It is an arithmetic number, because the mean of its divisors is an integer number (6709500).

Almost surely, 2^181440918 is an apocalyptic number.

181440918 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 181440918, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (214704000).

181440918 is an abundant number, since it is smaller than the sum of its proper divisors (247967082).

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

181440918 is a wasteful number, since it uses less digits than its factorization.

181440918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2106 (or 2100 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 181440918 is about 13470.0006681514. Note that the first 3 decimals coincide. The cubic root of 181440918 is about 566.1242324078.

The spelling of 181440918 in words is "one hundred eighty-one million, four hundred forty thousand, nine hundred eighteen".