21036204289 has 2 divisors, whose sum is σ = 21036204290. Its totient is φ = 21036204288.

The previous prime is 21036204281. The next prime is 21036204313. The reversal of 21036204289 is 98240263012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18827956225 + 2208248064 = 137215^2 + 46992^2 .

It is a cyclic number.

It is not a de Polignac number, because 21036204289 - 2³ = 21036204281 is a prime.

It is not a weakly prime, because it can be changed into another prime (21036204281) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10518102144 + 10518102145.

It is an arithmetic number, because the mean of its divisors is an integer number (10518102145).

Almost surely, 2^21036204289 is an apocalyptic number.

It is an amenable number.

21036204289 is a deficient number, since it is larger than the sum of its proper divisors (1).

21036204289 is an equidigital number, since it uses as much as digits as its factorization.

21036204289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 37.

The spelling of 21036204289 in words is "twenty-one billion, thirty-six million, two hundred four thousand, two hundred eighty-nine".