21422203421 has 8 divisors (see below), whose sum is σ = 22690492920. Its totient is φ = 20154820608.

The previous prime is 21422203417. The next prime is 21422203469. The reversal of 21422203421 is 12430222412.

It can be written as a sum of positive squares in 4 ways, for example, as 10898316025 + 10523887396 = 104395^2 + 102586^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21422203421 - 2² = 21422203417 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 (21422203721) 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, 177716 + ... + 272813.

It is an arithmetic number, because the mean of its divisors is an integer number (2836311615).

Almost surely, 2^21422203421 is an apocalyptic number.

It is an amenable number.

21422203421 is a deficient number, since it is larger than the sum of its proper divisors (1268289499).

21422203421 is a wasteful number, since it uses less digits than its factorization.

21422203421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 453343.

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

Adding to 21422203421 its reverse (12430222412), we get a palindrome (33852425833).

The spelling of 21422203421 in words is "twenty-one billion, four hundred twenty-two million, two hundred three thousand, four hundred twenty-one".