21272127 has 16 divisors (see below), whose sum is σ = 29002080. Its totient is φ = 13865472.

The previous prime is 21272123. The next prime is 21272129. The reversal of 21272127 is 72127212.

It is not a de Polignac number, because 21272127 - 2² = 21272123 is a prime.

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

It is a junction number, because it is equal to n+sod(n) for n = 21272097 and 21272106.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272123) 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, 29649 + ... + 30357.

It is an arithmetic number, because the mean of its divisors is an integer number (1812630).

Almost surely, 2^21272127 is an apocalyptic number.

21272127 is a deficient number, since it is larger than the sum of its proper divisors (7729953).

21272127 is a wasteful number, since it uses less digits than its factorization.

21272127 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 922.

The product of its digits is 784, while the sum is 24.

The square root of 21272127 is about 4612.1716143266. The cubic root of 21272127 is about 277.0790175420.

Adding to 21272127 its reverse (72127212), we get a palindrome (93399339).

The spelling of 21272127 in words is "twenty-one million, two hundred seventy-two thousand, one hundred twenty-seven".