40181831 has 2 divisors, whose sum is σ = 40181832. Its totient is φ = 40181830.

The previous prime is 40181821. The next prime is 40181861. The reversal of 40181831 is 13818104.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40181831 - 2⁶ = 40181767 is a prime.

It is a super-2 number, since 2×40181831² = 3229159085025122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is equal to p_2444039 and since 40181831 and 2444039 have the same sum of digits, it is a Honaker prime.

It is a self number, because there is not a number n which added to its sum of digits gives 40181831.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40181821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20090915 + 20090916.

It is an arithmetic number, because the mean of its divisors is an integer number (20090916).

Almost surely, 2^40181831 is an apocalyptic number.

40181831 is a deficient number, since it is larger than the sum of its proper divisors (1).

40181831 is an equidigital number, since it uses as much as digits as its factorization.

40181831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 40181831 is about 6338.9140237110. The cubic root of 40181831 is about 342.5126171493.

Adding to 40181831 its reverse (13818104), we get a palindrome (53999935).

The spelling of 40181831 in words is "forty million, one hundred eighty-one thousand, eight hundred thirty-one".