21200031305 has 16 divisors (see below), whose sum is σ = 26946463104. Its totient is φ = 15956478720.

The previous prime is 21200031301. The next prime is 21200031343. The reversal of 21200031305 is 50313000212.

It is not a de Polignac number, because 21200031305 - 2² = 21200031301 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21200031301) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 192554 + ... + 281916.

It is an arithmetic number, because the mean of its divisors is an integer number (1684153944).

Almost surely, 2^21200031305 is an apocalyptic number.

It is an amenable number.

21200031305 is a deficient number, since it is larger than the sum of its proper divisors (5746431799).

21200031305 is a wasteful number, since it uses less digits than its factorization.

21200031305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92176.

The product of its (nonzero) digits is 180, while the sum is 17.

Adding to 21200031305 its reverse (50313000212), we get a palindrome (71513031517).

The spelling of 21200031305 in words is "twenty-one billion, two hundred million, thirty-one thousand, three hundred five".