21420004444421 has 8 divisors (see below), whose sum is σ = 23368250325600. Its totient is φ = 19471920688240.

The previous prime is 21420004444381. The next prime is 21420004444481. The reversal of 21420004444421 is 12444440002412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21420004444421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21420004444481) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40254911 + ... + 40783548.

It is an arithmetic number, because the mean of its divisors is an integer number (2921031290700).

Almost surely, 2^{21420004444421} is an apocalyptic number.

It is an amenable number.

21420004444421 is a deficient number, since it is larger than the sum of its proper divisors (1948245881179).

21420004444421 is a wasteful number, since it uses less digits than its factorization.

21420004444421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81062499.

The product of its (nonzero) digits is 32768, while the sum is 32.

Adding to 21420004444421 its reverse (12444440002412), we get a palindrome (33864444446833).

The spelling of 21420004444421 in words is "twenty-one trillion, four hundred twenty billion, four million, four hundred forty-four thousand, four hundred twenty-one".