21272303 has 4 divisors (see below), whose sum is σ = 22908648. Its totient is φ = 19635960.

The previous prime is 21272297. The next prime is 21272311. The reversal of 21272303 is 30327212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21272303 - 2⁸ = 21272047 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21272323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 818153 + ... + 818178.

It is an arithmetic number, because the mean of its divisors is an integer number (5727162).

Almost surely, 2^21272303 is an apocalyptic number.

21272303 is a deficient number, since it is larger than the sum of its proper divisors (1636345).

21272303 is a wasteful number, since it uses less digits than its factorization.

21272303 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1636344.

The product of its (nonzero) digits is 504, while the sum is 20.

The square root of 21272303 is about 4612.1906942363. The cubic root of 21272303 is about 277.0797816996.

Adding to 21272303 its reverse (30327212), we get a palindrome (51599515).

The spelling of 21272303 in words is "twenty-one million, two hundred seventy-two thousand, three hundred three".