21402240011 has 4 divisors (see below), whose sum is σ = 21405436800. Its totient is φ = 21399043224.

The previous prime is 21402240007. The next prime is 21402240017. The reversal of 21402240011 is 11004220412.

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 21402240011 - 2² = 21402240007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21402240017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1588331 + ... + 1601748.

It is an arithmetic number, because the mean of its divisors is an integer number (5351359200).

Almost surely, 2^21402240011 is an apocalyptic number.

21402240011 is a deficient number, since it is larger than the sum of its proper divisors (3196789).

21402240011 is an equidigital number, since it uses as much as digits as its factorization.

21402240011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3196788.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21402240011 its reverse (11004220412), we get a palindrome (32406460423).

The spelling of 21402240011 in words is "twenty-one billion, four hundred two million, two hundred forty thousand, eleven".