21276165 has 16 divisors (see below), whose sum is σ = 34099200. Its totient is φ = 11328192.

The previous prime is 21276149. The next prime is 21276179. The reversal of 21276165 is 56167212.

It is not a de Polignac number, because 21276165 - 2⁴ = 21276149 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a congruent number.

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, 15996 + ... + 17274.

It is an arithmetic number, because the mean of its divisors is an integer number (2131200).

Almost surely, 2^21276165 is an apocalyptic number.

It is an amenable number.

21276165 is a deficient number, since it is larger than the sum of its proper divisors (12823035).

21276165 is a wasteful number, since it uses less digits than its factorization.

21276165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2396.

The product of its digits is 5040, while the sum is 30.

The square root of 21276165 is about 4612.6093482973. The cubic root of 21276165 is about 277.0965486878.

The spelling of 21276165 in words is "twenty-one million, two hundred seventy-six thousand, one hundred sixty-five".