21404401043 has 2 divisors, whose sum is σ = 21404401044. Its totient is φ = 21404401042.

The previous prime is 21404400977. The next prime is 21404401069. The reversal of 21404401043 is 34010440412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21404401043 - 2¹⁶ = 21404335507 is a prime.

It is not a weakly prime, because it can be changed into another prime (21404401093) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10702200521 + 10702200522.

It is an arithmetic number, because the mean of its divisors is an integer number (10702200522).

Almost surely, 2^21404401043 is an apocalyptic number.

21404401043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21404401043 is an equidigital number, since it uses as much as digits as its factorization.

21404401043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21404401043 its reverse (34010440412), we get a palindrome (55414841455).

The spelling of 21404401043 in words is "twenty-one billion, four hundred four million, four hundred one thousand, forty-three".