21404043411 has 4 divisors (see below), whose sum is σ = 28538724552. Its totient is φ = 14269362272.

The previous prime is 21404043407. The next prime is 21404043431. The reversal of 21404043411 is 11434040412.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21404043411 - 2² = 21404043407 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21404043431) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3567340566 + ... + 3567340571.

It is an arithmetic number, because the mean of its divisors is an integer number (7134681138).

Almost surely, 2^21404043411 is an apocalyptic number.

21404043411 is a deficient number, since it is larger than the sum of its proper divisors (7134681141).

21404043411 is an equidigital number, since it uses as much as digits as its factorization.

21404043411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7134681140.

The product of its (nonzero) digits is 1536, while the sum is 24.

Adding to 21404043411 its reverse (11434040412), we get a palindrome (32838083823).

The spelling of 21404043411 in words is "twenty-one billion, four hundred four million, forty-three thousand, four hundred eleven".