21108315529 has 4 divisors (see below), whose sum is σ = 24123789184. Its totient is φ = 18092841876.

The previous prime is 21108315517. The next prime is 21108315551. The reversal of 21108315529 is 92551380112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21108315529 - 2⁹ = 21108315017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21108315509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1507736817 + ... + 1507736830.

It is an arithmetic number, because the mean of its divisors is an integer number (6030947296).

Almost surely, 2^21108315529 is an apocalyptic number.

It is an amenable number.

21108315529 is a deficient number, since it is larger than the sum of its proper divisors (3015473655).

21108315529 is an equidigital number, since it uses as much as digits as its factorization.

21108315529 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3015473654.

The product of its (nonzero) digits is 21600, while the sum is 37.

The spelling of 21108315529 in words is "twenty-one billion, one hundred eight million, three hundred fifteen thousand, five hundred twenty-nine".