21404043373 has 2 divisors, whose sum is σ = 21404043374. Its totient is φ = 21404043372.

The previous prime is 21404043293. The next prime is 21404043407. The reversal of 21404043373 is 37334040412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12535489444 + 8868553929 = 111962^2 + 94173^2 .

It is a cyclic number.

It is not a de Polignac number, because 21404043373 - 2³³ = 12814108781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21404044373) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702021686 + 10702021687.

It is an arithmetic number, because the mean of its divisors is an integer number (10702021687).

Almost surely, 2^21404043373 is an apocalyptic number.

It is an amenable number.

21404043373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21404043373 is an equidigital number, since it uses as much as digits as its factorization.

21404043373 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 24192, while the sum is 31.

Adding to 21404043373 its reverse (37334040412), we get a palindrome (58738083785).

The spelling of 21404043373 in words is "twenty-one billion, four hundred four million, forty-three thousand, three hundred seventy-three".