21010234321 has 4 divisors (see below), whose sum is σ = 21020885172. Its totient is φ = 20999583472.

The previous prime is 21010234291. The next prime is 21010234339. The reversal of 21010234321 is 12343201012.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6278343696 + 14731890625 = 79236^2 + 121375^2 .

It is a cyclic number.

It is not a de Polignac number, because 21010234321 - 2²¹ = 21008137169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21010234351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5322466 + ... + 5326411.

It is an arithmetic number, because the mean of its divisors is an integer number (5255221293).

Almost surely, 2^21010234321 is an apocalyptic number.

It is an amenable number.

21010234321 is a deficient number, since it is larger than the sum of its proper divisors (10650851).

21010234321 is a wasteful number, since it uses less digits than its factorization.

21010234321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10650850.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21010234321 its reverse (12343201012), we get a palindrome (33353435333).

The spelling of 21010234321 in words is "twenty-one billion, ten million, two hundred thirty-four thousand, three hundred twenty-one".