21805087029 has 16 divisors (see below), whose sum is σ = 31725946944. Its totient is φ = 13211264000.

The previous prime is 21805087027. The next prime is 21805087033. The reversal of 21805087029 is 92078050812.

It is not a de Polignac number, because 21805087029 - 2¹ = 21805087027 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21805087027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15829 + ... + 209429.

It is an arithmetic number, because the mean of its divisors is an integer number (1982871684).

Almost surely, 2^21805087029 is an apocalyptic number.

It is an amenable number.

21805087029 is a deficient number, since it is larger than the sum of its proper divisors (9920859915).

21805087029 is a wasteful number, since it uses less digits than its factorization.

21805087029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197028.

The product of its (nonzero) digits is 80640, while the sum is 42.

The spelling of 21805087029 in words is "twenty-one billion, eight hundred five million, eighty-seven thousand, twenty-nine".