21427105 has 16 divisors (see below), whose sum is σ = 29942784. Its totient is φ = 14414400.

The previous prime is 21427103. The next prime is 21427121. The reversal of 21427105 is 50172412.

It is a happy number.

It is not a de Polignac number, because 21427105 - 2¹ = 21427103 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21427103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3921 + ... + 7630.

It is an arithmetic number, because the mean of its divisors is an integer number (1871424).

Almost surely, 2^21427105 is an apocalyptic number.

It is an amenable number.

21427105 is a deficient number, since it is larger than the sum of its proper divisors (8515679).

21427105 is a wasteful number, since it uses less digits than its factorization.

21427105 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11616.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 21427105 is about 4628.9421037641. The cubic root of 21427105 is about 277.7502760624.

Adding to 21427105 its reverse (50172412), we get a palindrome (71599517).

The spelling of 21427105 in words is "twenty-one million, four hundred twenty-seven thousand, one hundred five".