21130320389 has 2 divisors, whose sum is σ = 21130320390. Its totient is φ = 21130320388.

The previous prime is 21130320377. The next prime is 21130320397. The reversal of 21130320389 is 98302303112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20892389764 + 237930625 = 144542^2 + 15425^2 .

It is a cyclic number.

It is not a de Polignac number, because 21130320389 - 2²⁴ = 21113543173 is a prime.

It is a super-2 number, since 2×21130320389² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21130320689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565160194 + 10565160195.

It is an arithmetic number, because the mean of its divisors is an integer number (10565160195).

Almost surely, 2^21130320389 is an apocalyptic number.

It is an amenable number.

21130320389 is a deficient number, since it is larger than the sum of its proper divisors (1).

21130320389 is an equidigital number, since it uses as much as digits as its factorization.

21130320389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 32.

The spelling of 21130320389 in words is "twenty-one billion, one hundred thirty million, three hundred twenty thousand, three hundred eighty-nine".