21020365729 has 8 divisors (see below), whose sum is σ = 22933042272. Its totient is φ = 19107978240.

The previous prime is 21020365711. The next prime is 21020365753. The reversal of 21020365729 is 92756302012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21020365729 - 2⁹ = 21020365217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21020365759) 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 7 ways as a sum of consecutive naturals, for example, 97057 + ... + 226849.

It is an arithmetic number, because the mean of its divisors is an integer number (2866630284).

Almost surely, 2^21020365729 is an apocalyptic number.

It is an amenable number.

21020365729 is a deficient number, since it is larger than the sum of its proper divisors (1912676543).

21020365729 is a wasteful number, since it uses less digits than its factorization.

21020365729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144527.

The product of its (nonzero) digits is 45360, while the sum is 37.

The spelling of 21020365729 in words is "twenty-one billion, twenty million, three hundred sixty-five thousand, seven hundred twenty-nine".