21434204305 has 8 divisors (see below), whose sum is σ = 25722869544. Its totient is φ = 17146147200.

The previous prime is 21434204291. The next prime is 21434204329. The reversal of 21434204305 is 50340243412.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 29343889 + 21404860416 = 5417^2 + 146304^2 .

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

It is not a de Polignac number, because 21434204305 - 2⁵ = 21434204273 is a prime.

It is a super-2 number, since 2×21434204305² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70516 + ... + 218725.

It is an arithmetic number, because the mean of its divisors is an integer number (3215358693).

Almost surely, 2^21434204305 is an apocalyptic number.

It is an amenable number.

21434204305 is a deficient number, since it is larger than the sum of its proper divisors (4288665239).

21434204305 is a wasteful number, since it uses less digits than its factorization.

21434204305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304067.

The product of its (nonzero) digits is 11520, while the sum is 28.

Adding to 21434204305 its reverse (50340243412), we get a palindrome (71774447717).

The spelling of 21434204305 in words is "twenty-one billion, four hundred thirty-four million, two hundred four thousand, three hundred five".