21430640009 has 2 divisors, whose sum is σ = 21430640010. Its totient is φ = 21430640008.

The previous prime is 21430639931. The next prime is 21430640059. The reversal of 21430640009 is 90004603412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11032351225 + 10398288784 = 105035^2 + 101972^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21430640009 is a prime.

It is not a weakly prime, because it can be changed into another prime (21430640059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10715320004 + 10715320005.

It is an arithmetic number, because the mean of its divisors is an integer number (10715320005).

Almost surely, 2^21430640009 is an apocalyptic number.

It is an amenable number.

21430640009 is a deficient number, since it is larger than the sum of its proper divisors (1).

21430640009 is an equidigital number, since it uses as much as digits as its factorization.

21430640009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5184, while the sum is 29.

The spelling of 21430640009 in words is "twenty-one billion, four hundred thirty million, six hundred forty thousand, nine".