21320020105 has 8 divisors (see below), whose sum is σ = 25595403264. Its totient is φ = 17048430000.

The previous prime is 21320020091. The next prime is 21320020121. The reversal of 21320020105 is 50102002312.

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

It is not a de Polignac number, because 21320020105 - 2⁹ = 21320019593 is a prime.

It is a super-2 number, since 2×21320020105² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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, 935881 + ... + 958390.

It is an arithmetic number, because the mean of its divisors is an integer number (3199425408).

Almost surely, 2^21320020105 is an apocalyptic number.

It is an amenable number.

21320020105 is a deficient number, since it is larger than the sum of its proper divisors (4275383159).

21320020105 is a wasteful number, since it uses less digits than its factorization.

21320020105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896527.

The product of its (nonzero) digits is 120, while the sum is 16.

Adding to 21320020105 its reverse (50102002312), we get a palindrome (71422022417).

The spelling of 21320020105 in words is "twenty-one billion, three hundred twenty million, twenty thousand, one hundred five".