21810634529 has 2 divisors, whose sum is σ = 21810634530. Its totient is φ = 21810634528.

The previous prime is 21810634487. The next prime is 21810634543. The reversal of 21810634529 is 92543601812.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17083797025 + 4726837504 = 130705^2 + 68752^2 .

It is a cyclic number.

It is not a de Polignac number, because 21810634529 - 2¹² = 21810630433 is a prime.

It is not a weakly prime, because it can be changed into another prime (21810634579) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10905317264 + 10905317265.

It is an arithmetic number, because the mean of its divisors is an integer number (10905317265).

Almost surely, 2^21810634529 is an apocalyptic number.

It is an amenable number.

21810634529 is a deficient number, since it is larger than the sum of its proper divisors (1).

21810634529 is an equidigital number, since it uses as much as digits as its factorization.

21810634529 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 103680, while the sum is 41.

The spelling of 21810634529 in words is "twenty-one billion, eight hundred ten million, six hundred thirty-four thousand, five hundred twenty-nine".