181387040 has 48 divisors (see below), whose sum is σ = 431069688. Its totient is φ = 72124416.

The previous prime is 181387033. The next prime is 181387043. The reversal of 181387040 is 40783181.

It can be written as a sum of positive squares in 4 ways, for example, as 164968336 + 16418704 = 12844^2 + 4052^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a junction number, because it is equal to n+sod(n) for n = 181386988 and 181387006.

It is not an unprimeable number, because it can be changed into a prime (181387043) 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, 24404 + ... + 30956.

Almost surely, 2^181387040 is an apocalyptic number.

181387040 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 181387040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215534844).

181387040 is an abundant number, since it is smaller than the sum of its proper divisors (249682648).

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

181387040 is a wasteful number, since it uses less digits than its factorization.

181387040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6741 (or 6733 counting only the distinct ones).

The product of its (nonzero) digits is 5376, while the sum is 32.

The square root of 181387040 is about 13468.0005940006. Note that the first 3 decimals coincide. The cubic root of 181387040 is about 566.0681909126.

The spelling of 181387040 in words is "one hundred eighty-one million, three hundred eighty-seven thousand, forty".