40509181 has 8 divisors (see below), whose sum is σ = 43318584. Its totient is φ = 37747200.

The previous prime is 40509173. The next prime is 40509193. The reversal of 40509181 is 18190504.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 12313081 + 28196100 = 3509^2 + 5310^2 .

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 40509181 - 2³ = 40509173 is a prime.

It is a super-2 number, since 2×40509181² = 3281987490581522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40549181) 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, 10080 + ... + 13513.

It is an arithmetic number, because the mean of its divisors is an integer number (5414823).

Almost surely, 2^40509181 is an apocalyptic number.

It is an amenable number.

40509181 is a deficient number, since it is larger than the sum of its proper divisors (2809403).

40509181 is a wasteful number, since it uses less digits than its factorization.

40509181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23711.

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 40509181 is about 6364.6823172881. The cubic root of 40509181 is about 343.4402204880.

Adding to 40509181 its reverse (18190504), we get a palindrome (58699685).

It can be divided in two parts, 4050 and 9181, that added together give a palindrome (13231).

The spelling of 40509181 in words is "forty million, five hundred nine thousand, one hundred eighty-one".