40013531 has 4 divisors (see below), whose sum is σ = 40050912. Its totient is φ = 39976152.

The previous prime is 40013507. The next prime is 40013551. The reversal of 40013531 is 13531004.

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

It is a cyclic number.

It is not a de Polignac number, because 40013531 - 2²² = 35819227 is a prime.

It is a super-2 number, since 2×40013531² = 3202165326175922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40013551) 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, 17036 + ... + 19241.

It is an arithmetic number, because the mean of its divisors is an integer number (10012728).

Almost surely, 2^40013531 is an apocalyptic number.

40013531 is a deficient number, since it is larger than the sum of its proper divisors (37381).

40013531 is a wasteful number, since it uses less digits than its factorization.

40013531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37380.

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 40013531 is about 6325.6249493627. The cubic root of 40013531 is about 342.0337477954.

Adding to 40013531 its reverse (13531004), we get a palindrome (53544535).

It can be divided in two parts, 400 and 13531, that added together give a palindrome (13931).

The spelling of 40013531 in words is "forty million, thirteen thousand, five hundred thirty-one".