21136105 has 8 divisors (see below), whose sum is σ = 25389000. Its totient is φ = 16891776.

The previous prime is 21136069. The next prime is 21136123. The reversal of 21136105 is 50163112.

It can be written as a sum of positive squares in 4 ways, for example, as 5517801 + 15618304 = 2349^2 + 3952^2 .

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 21136105 - 2⁹ = 21135593 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6381 + ... + 9109.

It is an arithmetic number, because the mean of its divisors is an integer number (3173625).

Almost surely, 2^21136105 is an apocalyptic number.

It is an amenable number.

21136105 is a deficient number, since it is larger than the sum of its proper divisors (4252895).

21136105 is a wasteful number, since it uses less digits than its factorization.

21136105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4283.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 21136105 is about 4597.4019837295. The cubic root of 21136105 is about 276.4871716812.

Adding to 21136105 its reverse (50163112), we get a palindrome (71299217).

The spelling of 21136105 in words is "twenty-one million, one hundred thirty-six thousand, one hundred five".