21115430573 has 2 divisors, whose sum is σ = 21115430574. Its totient is φ = 21115430572.

The previous prime is 21115430563. The next prime is 21115430587. The reversal of 21115430573 is 37503451112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18631704004 + 2483726569 = 136498^2 + 49837^2 .

It is a cyclic number.

It is not a de Polignac number, because 21115430573 - 2¹⁴ = 21115414189 is a prime.

It is a super-2 number, since 2×21115430573² (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 (21115430543) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10557715286 + 10557715287.

It is an arithmetic number, because the mean of its divisors is an integer number (10557715287).

Almost surely, 2^21115430573 is an apocalyptic number.

It is an amenable number.

21115430573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21115430573 is an equidigital number, since it uses as much as digits as its factorization.

21115430573 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12600, while the sum is 32.

Adding to 21115430573 its reverse (37503451112), we get a palindrome (58618881685).

The spelling of 21115430573 in words is "twenty-one billion, one hundred fifteen million, four hundred thirty thousand, five hundred seventy-three".