21102320105 has 8 divisors (see below), whose sum is σ = 25332702792. Its totient is φ = 16875243648.

The previous prime is 21102320101. The next prime is 21102320111. The reversal of 21102320105 is 50102320112.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 450330841 + 20651989264 = 21221^2 + 143708^2 .

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 21102320105 - 2² = 21102320101 is a prime.

It is a super-2 number, since 2×21102320105² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21102320101) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 812492 + ... + 838061.

It is an arithmetic number, because the mean of its divisors is an integer number (3166587849).

Almost surely, 2^21102320105 is an apocalyptic number.

It is an amenable number.

21102320105 is a deficient number, since it is larger than the sum of its proper divisors (4230382687).

21102320105 is a wasteful number, since it uses less digits than its factorization.

21102320105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1653115.

The product of its (nonzero) digits is 120, while the sum is 17.

Adding to 21102320105 its reverse (50102320112), we get a palindrome (71204640217).

The spelling of 21102320105 in words is "twenty-one billion, one hundred two million, three hundred twenty thousand, one hundred five".