181281240 has 160 divisors (see below), whose sum is σ = 696437280. Its totient is φ = 41430528.

The previous prime is 181281229. The next prime is 181281257. The reversal of 181281240 is 42182181.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 39 ways as a sum of consecutive naturals, for example, 18684 + ... + 26676.

It is an arithmetic number, because the mean of its divisors is an integer number (4352733).

Almost surely, 2^181281240 is an apocalyptic number.

181281240 is a gapful number since it is divisible by the number (10) 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 181281240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (348218640).

181281240 is an abundant number, since it is smaller than the sum of its proper divisors (515156040).

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

181281240 is a wasteful number, since it uses less digits than its factorization.

181281240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8023 (or 8010 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 27.

The square root of 181281240 is about 13464.0721923198. The cubic root of 181281240 is about 565.9581101655.

The spelling of 181281240 in words is "one hundred eighty-one million, two hundred eighty-one thousand, two hundred forty".