21203453659 has 2 divisors, whose sum is σ = 21203453660. Its totient is φ = 21203453658.

The previous prime is 21203453657. The next prime is 21203453669. The reversal of 21203453659 is 95635430212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203453659 - 2¹ = 21203453657 is a prime.

Together with 21203453657, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21203453657) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601726829 + 10601726830.

It is an arithmetic number, because the mean of its divisors is an integer number (10601726830).

Almost surely, 2^21203453659 is an apocalyptic number.

21203453659 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203453659 is an equidigital number, since it uses as much as digits as its factorization.

21203453659 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 194400, while the sum is 40.

The spelling of 21203453659 in words is "twenty-one billion, two hundred three million, four hundred fifty-three thousand, six hundred fifty-nine".