21168105 has 24 divisors (see below), whose sum is σ = 38793792. Its totient is φ = 9655296.

The previous prime is 21168101. The next prime is 21168113. The reversal of 21168105 is 50186112.

It is not a de Polignac number, because 21168105 - 2² = 21168101 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21168101) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 46921 + ... + 47369.

It is an arithmetic number, because the mean of its divisors is an integer number (1616408).

Almost surely, 2^21168105 is an apocalyptic number.

It is an amenable number.

21168105 is a deficient number, since it is larger than the sum of its proper divisors (17625687).

21168105 is an frugal number, since it uses more digits than its factorization.

21168105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913 (or 464 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 21168105 is about 4600.8808939159. The cubic root of 21168105 is about 276.6266349073.

The spelling of 21168105 in words is "twenty-one million, one hundred sixty-eight thousand, one hundred five".