21123234499 has 2 divisors, whose sum is σ = 21123234500. Its totient is φ = 21123234498.

The previous prime is 21123234497. The next prime is 21123234589. The reversal of 21123234499 is 99443232112.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21123234499 - 2¹ = 21123234497 is a prime.

Together with 21123234497, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21123234497) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561617249 + 10561617250.

It is an arithmetic number, because the mean of its divisors is an integer number (10561617250).

Almost surely, 2^21123234499 is an apocalyptic number.

21123234499 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123234499 is an equidigital number, since it uses as much as digits as its factorization.

21123234499 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 40.

The spelling of 21123234499 in words is "twenty-one billion, one hundred twenty-three million, two hundred thirty-four thousand, four hundred ninety-nine".