21231430999 has 2 divisors, whose sum is σ = 21231431000. Its totient is φ = 21231430998.

The previous prime is 21231430981. The next prime is 21231431009. The reversal of 21231430999 is 99903413212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21231430999 - 2¹⁵ = 21231398231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21231430919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615715499 + 10615715500.

It is an arithmetic number, because the mean of its divisors is an integer number (10615715500).

Almost surely, 2^21231430999 is an apocalyptic number.

21231430999 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231430999 is an equidigital number, since it uses as much as digits as its factorization.

21231430999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 43.

The spelling of 21231430999 in words is "twenty-one billion, two hundred thirty-one million, four hundred thirty thousand, nine hundred ninety-nine".