40440042421 has 2 divisors, whose sum is σ = 40440042422. Its totient is φ = 40440042420.

The previous prime is 40440042397. The next prime is 40440042427. The reversal of 40440042421 is 12424004404.

40440042421 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., 36781486225 + 3658556196 = 191785^2 + 60486^2 .

It is a cyclic number.

It is not a de Polignac number, because 40440042421 - 2¹¹ = 40440040373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40440042427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20220021210 + 20220021211.

It is an arithmetic number, because the mean of its divisors is an integer number (20220021211).

Almost surely, 2^40440042421 is an apocalyptic number.

It is an amenable number.

40440042421 is a deficient number, since it is larger than the sum of its proper divisors (1).

40440042421 is an equidigital number, since it uses as much as digits as its factorization.

40440042421 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4096, while the sum is 25.

Adding to 40440042421 its reverse (12424004404), we get a palindrome (52864046825).

The spelling of 40440042421 in words is "forty billion, four hundred forty million, forty-two thousand, four hundred twenty-one".