21272015 has 8 divisors (see below), whose sum is σ = 27028080. Its totient is φ = 16016512.

The previous prime is 21272011. The next prime is 21272021. The reversal of 21272015 is 51027212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21272015 - 2² = 21272011 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272011) 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 7 ways as a sum of consecutive naturals, for example, 125045 + ... + 125214.

It is an arithmetic number, because the mean of its divisors is an integer number (3378510).

Almost surely, 2^21272015 is an apocalyptic number.

21272015 is a deficient number, since it is larger than the sum of its proper divisors (5756065).

21272015 is a wasteful number, since it uses less digits than its factorization.

21272015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250281.

The product of its (nonzero) digits is 280, while the sum is 20.

The square root of 21272015 is about 4612.1594725248. The cubic root of 21272015 is about 277.0785312577.

Adding to 21272015 its reverse (51027212), we get a palindrome (72299227).

It can be divided in two parts, 212 and 72015, that added together give a palindrome (72227).

The spelling of 21272015 in words is "twenty-one million, two hundred seventy-two thousand, fifteen".