21107 has 2 divisors, whose sum is σ = 21108.
Its totient is φ = 21106.
The previous prime is 21101. The next prime is 21121. The reversal of 21107 is 70112.
Adding to 21107 its reverse (70112), we get a palindrome (91219).
It can be divided in two parts, 21 and 107, that added together give a 7-th power (128 = 27).
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 21107 - 212 = 17011 is a prime.
It is a plaindrome in base 14.
It is not a weakly prime, because it can be changed into another prime (21101) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10553 + 10554.
It is an arithmetic number, because the mean of its divisors is an integer number (10554).
221107 is an apocalyptic number.
21107 is a deficient number, since it is larger than the sum of its proper divisors (1).
21107 is an equidigital number, since it uses as much as digits as its factorization.
21107 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 14, while the sum is 11.
The square root of 21107 is about 145.2824834589.
The cubic root of 21107 is about 27.6360203228.
The spelling of 21107 in words is "twenty-one thousand, one hundred seven", and thus it is an iban number.