40009181 has 4 divisors (see below), whose sum is σ = 40032864. Its totient is φ = 39985500.

The previous prime is 40009169. The next prime is 40009201. The reversal of 40009181 is 18190004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40009181 is a prime.

It is a super-2 number, since 2×40009181² = 3201469128581522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40009141) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9095 + ... + 12756.

It is an arithmetic number, because the mean of its divisors is an integer number (10008216).

Almost surely, 2^40009181 is an apocalyptic number.

It is an amenable number.

40009181 is a deficient number, since it is larger than the sum of its proper divisors (23683).

40009181 is a wasteful number, since it uses less digits than its factorization.

40009181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23682.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 40009181 is about 6325.2811004729. The cubic root of 40009181 is about 342.0213528157.

Adding to 40009181 its reverse (18190004), we get a palindrome (58199185).

The spelling of 40009181 in words is "forty million, nine thousand, one hundred eighty-one".