21380272 has 10 divisors (see below), whose sum is σ = 41424308. Its totient is φ = 10690128.

The previous prime is 21380269. The next prime is 21380273. The reversal of 21380272 is 27208312.

It is not an unprimeable number, because it can be changed into a prime (21380273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 668118 + ... + 668149.

Almost surely, 2^21380272 is an apocalyptic number.

It is an amenable number.

21380272 is a deficient number, since it is larger than the sum of its proper divisors (20044036).

21380272 is a wasteful number, since it uses less digits than its factorization.

21380272 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1336275 (or 1336269 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 21380272 is about 4623.8806212964. The cubic root of 21380272 is about 277.5477698246.

Adding to 21380272 its reverse (27208312), we get a palindrome (48588584).

The spelling of 21380272 in words is "twenty-one million, three hundred eighty thousand, two hundred seventy-two".