40031021 has 2 divisors, whose sum is σ = 40031022. Its totient is φ = 40031020.

The previous prime is 40031011. The next prime is 40031029. The reversal of 40031021 is 12013004.

It is a happy number.

40031021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 37515625 + 2515396 = 6125^2 + 1586^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40031021 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 40030993 and 40031011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40031029) 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 as a sum of consecutive naturals, namely, 20015510 + 20015511.

It is an arithmetic number, because the mean of its divisors is an integer number (20015511).

Almost surely, 2^40031021 is an apocalyptic number.

It is an amenable number.

40031021 is a deficient number, since it is larger than the sum of its proper divisors (1).

40031021 is an equidigital number, since it uses as much as digits as its factorization.

40031021 is an odious number, because the sum of its binary digits is odd.

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

The square root of 40031021 is about 6327.0072704241. The cubic root of 40031021 is about 342.0835750972.

Adding to 40031021 its reverse (12013004), we get a palindrome (52044025).

The spelling of 40031021 in words is "forty million, thirty-one thousand, twenty-one".