21424004043461 has 2 divisors, whose sum is σ = 21424004043462. Its totient is φ = 21424004043460.

The previous prime is 21424004043413. The next prime is 21424004043557. The reversal of 21424004043461 is 16434040042412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20764708762561 + 659295280900 = 4556831^2 + 811970^2 .

It is a cyclic number.

It is not a de Polignac number, because 21424004043461 - 2⁶ = 21424004043397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21424004043961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712002021730 + 10712002021731.

It is an arithmetic number, because the mean of its divisors is an integer number (10712002021731).

Almost surely, 2^{21424004043461} is an apocalyptic number.

It is an amenable number.

21424004043461 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424004043461 is an equidigital number, since it uses as much as digits as its factorization.

21424004043461 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 73728, while the sum is 35.

Adding to 21424004043461 its reverse (16434040042412), we get a palindrome (37858044085873).

The spelling of 21424004043461 in words is "twenty-one trillion, four hundred twenty-four billion, four million, forty-three thousand, four hundred sixty-one".