21205159229 has 2 divisors, whose sum is σ = 21205159230. Its totient is φ = 21205159228.

The previous prime is 21205159193. The next prime is 21205159259. The reversal of 21205159229 is 92295150212.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13613522329 + 7591636900 = 116677^2 + 87130^2 .

It is a cyclic number.

It is not a de Polignac number, because 21205159229 - 2³² = 16910191933 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21205159192 and 21205159201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21205159259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10602579614 + 10602579615.

It is an arithmetic number, because the mean of its divisors is an integer number (10602579615).

Almost surely, 2^21205159229 is an apocalyptic number.

It is an amenable number.

21205159229 is a deficient number, since it is larger than the sum of its proper divisors (1).

21205159229 is an equidigital number, since it uses as much as digits as its factorization.

21205159229 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32400, while the sum is 38.

The spelling of 21205159229 in words is "twenty-one billion, two hundred five million, one hundred fifty-nine thousand, two hundred twenty-nine".