21234175321 has 2 divisors, whose sum is σ = 21234175322. Its totient is φ = 21234175320.

The previous prime is 21234175189. The next prime is 21234175331. The reversal of 21234175321 is 12357143212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15790686921 + 5443488400 = 125661^2 + 73780^2 .

It is a cyclic number.

It is not a de Polignac number, because 21234175321 - 2⁹ = 21234174809 is a prime.

It is not a weakly prime, because it can be changed into another prime (21234175331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10617087660 + 10617087661.

It is an arithmetic number, because the mean of its divisors is an integer number (10617087661).

Almost surely, 2^21234175321 is an apocalyptic number.

It is an amenable number.

21234175321 is a deficient number, since it is larger than the sum of its proper divisors (1).

21234175321 is an equidigital number, since it uses as much as digits as its factorization.

21234175321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10080, while the sum is 31.

The spelling of 21234175321 in words is "twenty-one billion, two hundred thirty-four million, one hundred seventy-five thousand, three hundred twenty-one".