21559636229 has 2 divisors, whose sum is σ = 21559636230. Its totient is φ = 21559636228.

The previous prime is 21559636213. The next prime is 21559636297. The reversal of 21559636229 is 92263695512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15221884129 + 6337752100 = 123377^2 + 79610^2 .

It is a cyclic number.

It is not a de Polignac number, because 21559636229 - 2⁴ = 21559636213 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21559632229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10779818114 + 10779818115.

It is an arithmetic number, because the mean of its divisors is an integer number (10779818115).

Almost surely, 2^21559636229 is an apocalyptic number.

It is an amenable number.

21559636229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21559636229 is an equidigital number, since it uses as much as digits as its factorization.

21559636229 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1749600, while the sum is 50.

The spelling of 21559636229 in words is "twenty-one billion, five hundred fifty-nine million, six hundred thirty-six thousand, two hundred twenty-nine".