21120105 has 8 divisors (see below), whose sum is σ = 33792192. Its totient is φ = 11264048.

The previous prime is 21120089. The next prime is 21120109. The reversal of 21120105 is 50102112.

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 21120105 - 2⁴ = 21120089 is a prime.

It is a super-2 number, since 2×21120105² = 892117670422050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21120109) 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, 703989 + ... + 704018.

It is an arithmetic number, because the mean of its divisors is an integer number (4224024).

Almost surely, 2^21120105 is an apocalyptic number.

It is an amenable number.

21120105 is a deficient number, since it is larger than the sum of its proper divisors (12672087).

21120105 is a wasteful number, since it uses less digits than its factorization.

21120105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1408015.

The product of its (nonzero) digits is 20, while the sum is 12.

The square root of 21120105 is about 4595.6615410624. The cubic root of 21120105 is about 276.4173872770.

Adding to 21120105 its reverse (50102112), we get a palindrome (71222217).

The spelling of 21120105 in words is "twenty-one million, one hundred twenty thousand, one hundred five".