40021531 has 16 divisors (see below), whose sum is σ = 45308160. Its totient is φ = 35030880.

The previous prime is 40021517. The next prime is 40021547. The reversal of 40021531 is 13512004.

40021531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 40021531 - 2²⁵ = 6467099 is a prime.

It is a super-2 number, since 2×40021531² = 3203445887167922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40021561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43090 + ... + 44008.

It is an arithmetic number, because the mean of its divisors is an integer number (2831760).

Almost surely, 2^40021531 is an apocalyptic number.

40021531 is a deficient number, since it is larger than the sum of its proper divisors (5286629).

40021531 is a wasteful number, since it uses less digits than its factorization.

40021531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1074.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 40021531 is about 6326.2572663464. The cubic root of 40021531 is about 342.0565408155.

Adding to 40021531 its reverse (13512004), we get a palindrome (53533535).

The spelling of 40021531 in words is "forty million, twenty-one thousand, five hundred thirty-one".