21271264 has 24 divisors (see below), whose sum is σ = 47860848. Its totient is φ = 9116160.

The previous prime is 21271259. The next prime is 21271277. The reversal of 21271264 is 46217212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47257 + ... + 47704.

It is an arithmetic number, because the mean of its divisors is an integer number (1994202).

Almost surely, 2^21271264 is an apocalyptic number.

It is an amenable number.

21271264 is an abundant number, since it is smaller than the sum of its proper divisors (26589584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21271264 is an equidigital number, since it uses as much as digits as its factorization.

21271264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94978 (or 94970 counting only the distinct ones).

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

The square root of 21271264 is about 4612.0780565814. The cubic root of 21271264 is about 277.0752705036.

Adding to 21271264 its reverse (46217212), we get a palindrome (67488476).

The spelling of 21271264 in words is "twenty-one million, two hundred seventy-one thousand, two hundred sixty-four".