40021013 has 8 divisors (see below), whose sum is σ = 41265720. Its totient is φ = 38784960.

The previous prime is 40021001. The next prime is 40021021. The reversal of 40021013 is 31012004.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 305809 + 39715204 = 553^2 + 6302^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 40021013 - 2⁴ = 40020997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40020985 and 40021003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40021313) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7943 + ... + 11963.

It is an arithmetic number, because the mean of its divisors is an integer number (5158215).

Almost surely, 2^40021013 is an apocalyptic number.

It is an amenable number.

40021013 is a deficient number, since it is larger than the sum of its proper divisors (1244707).

40021013 is a wasteful number, since it uses less digits than its factorization.

40021013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4327.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 40021013 is about 6326.2163257353. The cubic root of 40021013 is about 342.0550650594.

Adding to 40021013 its reverse (31012004), we get a palindrome (71033017).

Subtracting from 40021013 its reverse (31012004), we obtain a palindrome (9009009).

The spelling of 40021013 in words is "forty million, twenty-one thousand, thirteen".