40431581 has 4 divisors (see below), whose sum is σ = 40447932. Its totient is φ = 40415232.

The previous prime is 40431571. The next prime is 40431623. The reversal of 40431581 is 18513404.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24900100 + 15531481 = 4990^2 + 3941^2 .

It is a cyclic number.

It is not a de Polignac number, because 40431581 - 2¹⁰ = 40430557 is a prime.

It is a super-2 number, since 2×40431581² = 3269425484319122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 40431581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40431511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3620 + ... + 9693.

It is an arithmetic number, because the mean of its divisors is an integer number (10111983).

Almost surely, 2^40431581 is an apocalyptic number.

It is an amenable number.

40431581 is a deficient number, since it is larger than the sum of its proper divisors (16351).

40431581 is a wasteful number, since it uses less digits than its factorization.

40431581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16350.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 40431581 is about 6358.5832541534. The cubic root of 40431581 is about 343.2207805467.

Adding to 40431581 its reverse (18513404), we get a palindrome (58944985).

The spelling of 40431581 in words is "forty million, four hundred thirty-one thousand, five hundred eighty-one".