40172181 has 16 divisors (see below), whose sum is σ = 61421568. Its totient is φ = 22878000.

The previous prime is 40172177. The next prime is 40172183. The reversal of 40172181 is 18127104.

It is not a de Polignac number, because 40172181 - 2² = 40172177 is a prime.

It is a super-2 number, since 2×40172181² = 3227608252593522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40172183) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3456 + ... + 9606.

It is an arithmetic number, because the mean of its divisors is an integer number (3838848).

Almost surely, 2^40172181 is an apocalyptic number.

It is an amenable number.

40172181 is a deficient number, since it is larger than the sum of its proper divisors (21249387).

40172181 is a wasteful number, since it uses less digits than its factorization.

40172181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6472.

The product of its (nonzero) digits is 448, while the sum is 24.

The square root of 40172181 is about 6338.1528066149. The cubic root of 40172181 is about 342.4851958721.

Adding to 40172181 its reverse (18127104), we get a palindrome (58299285).

The spelling of 40172181 in words is "forty million, one hundred seventy-two thousand, one hundred eighty-one".