21106065 has 32 divisors (see below), whose sum is σ = 35582976. Its totient is φ = 10662080.

The previous prime is 21106051. The next prime is 21106067. The reversal of 21106065 is 56060112.

It is a happy number.

It is not a de Polignac number, because 21106065 - 2⁴ = 21106049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21106067) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 44962 + ... + 45428.

It is an arithmetic number, because the mean of its divisors is an integer number (1111968).

Almost surely, 2^21106065 is an apocalyptic number.

It is an amenable number.

21106065 is a deficient number, since it is larger than the sum of its proper divisors (14476911).

21106065 is a wasteful number, since it uses less digits than its factorization.

21106065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 629.

The product of its (nonzero) digits is 360, while the sum is 21.

The square root of 21106065 is about 4594.1337594807. The cubic root of 21106065 is about 276.3561224237.

Adding to 21106065 its reverse (56060112), we get a palindrome (77166177).

The spelling of 21106065 in words is "twenty-one million, one hundred six thousand, sixty-five".