21271648 has 12 divisors (see below), whose sum is σ = 41878620. Its totient is φ = 10635808.

The previous prime is 21271643. The next prime is 21271667. The reversal of 21271648 is 84617212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21271643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332338 + ... + 332401.

It is an arithmetic number, because the mean of its divisors is an integer number (3489885).

Almost surely, 2^21271648 is an apocalyptic number.

It is an amenable number.

21271648 is a deficient number, since it is larger than the sum of its proper divisors (20606972).

21271648 is an equidigital number, since it uses as much as digits as its factorization.

21271648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 664749 (or 664741 counting only the distinct ones).

The product of its digits is 5376, while the sum is 31.

The square root of 21271648 is about 4612.1196862180. The cubic root of 21271648 is about 277.0769377962.

The spelling of 21271648 in words is "twenty-one million, two hundred seventy-one thousand, six hundred forty-eight".