21200105 has 16 divisors (see below), whose sum is σ = 28356480. Its totient is φ = 15121152.

The previous prime is 21200093. The next prime is 21200117. The reversal of 21200105 is 50100212.

It is an interprime number because it is at equal distance from previous prime (21200093) and next prime (21200117).

It is a cyclic number.

It is not a de Polignac number, because 21200105 - 2⁶ = 21200041 is a prime.

It is a super-2 number, since 2×21200105² = 898888904022050, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4949 + ... + 8178.

It is an arithmetic number, because the mean of its divisors is an integer number (1772280).

Almost surely, 2^21200105 is an apocalyptic number.

It is an amenable number.

21200105 is a deficient number, since it is larger than the sum of its proper divisors (7156375).

21200105 is a wasteful number, since it uses less digits than its factorization.

21200105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13168.

The product of its (nonzero) digits is 20, while the sum is 11.

The square root of 21200105 is about 4604.3571755458. The cubic root of 21200105 is about 276.7659576523.

Adding to 21200105 its reverse (50100212), we get a palindrome (71300317).

The spelling of 21200105 in words is "twenty-one million, two hundred thousand, one hundred five".