21272648 has 8 divisors (see below), whose sum is σ = 39886230. Its totient is φ = 10636320.

The previous prime is 21272621. The next prime is 21272681. The reversal of 21272648 is 84627212.

It can be written as a sum of positive squares in only one way, i.e., 21141604 + 131044 = 4598^2 + 362^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1329533 + ... + 1329548.

Almost surely, 2^21272648 is an apocalyptic number.

It is an amenable number.

21272648 is a deficient number, since it is larger than the sum of its proper divisors (18613582).

21272648 is a wasteful number, since it uses less digits than its factorization.

21272648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659087 (or 2659083 counting only the distinct ones).

The product of its digits is 10752, while the sum is 32.

The square root of 21272648 is about 4612.2280949667. The cubic root of 21272648 is about 277.0812796099.

The spelling of 21272648 in words is "twenty-one million, two hundred seventy-two thousand, six hundred forty-eight".