21430030073 has 2 divisors, whose sum is σ = 21430030074. Its totient is φ = 21430030072.

The previous prime is 21430030003. The next prime is 21430030081. The reversal of 21430030073 is 37003003412.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18527837689 + 2902192384 = 136117^2 + 53872^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21430030073 is a prime.

It is not a weakly prime, because it can be changed into another prime (21430030003) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715015036 + 10715015037.

It is an arithmetic number, because the mean of its divisors is an integer number (10715015037).

Almost surely, 2^21430030073 is an apocalyptic number.

It is an amenable number.

21430030073 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430030073 is an equidigital number, since it uses as much as digits as its factorization.

21430030073 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1512, while the sum is 23.

Adding to 21430030073 its reverse (37003003412), we get a palindrome (58433033485).

The spelling of 21430030073 in words is "twenty-one billion, four hundred thirty million, thirty thousand, seventy-three".