21606363959 has 2 divisors, whose sum is σ = 21606363960. Its totient is φ = 21606363958.

The previous prime is 21606363949. The next prime is 21606363991. The reversal of 21606363959 is 95936360612.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21606363959 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21606363949) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10803181979 + 10803181980.

It is an arithmetic number, because the mean of its divisors is an integer number (10803181980).

Almost surely, 2^21606363959 is an apocalyptic number.

21606363959 is a deficient number, since it is larger than the sum of its proper divisors (1).

21606363959 is an equidigital number, since it uses as much as digits as its factorization.

21606363959 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1574640, while the sum is 50.

The spelling of 21606363959 in words is "twenty-one billion, six hundred six million, three hundred sixty-three thousand, nine hundred fifty-nine".