21271208 has 32 divisors (see below), whose sum is σ = 47055360. Its totient is φ = 8821440.

The previous prime is 21271207. The next prime is 21271223. The reversal of 21271208 is 80217212.

It is not an unprimeable number, because it can be changed into a prime (21271207) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4391 + ... + 7862.

It is an arithmetic number, because the mean of its divisors is an integer number (1470480).

Almost surely, 2^21271208 is an apocalyptic number.

21271208 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21271208 is an abundant number, since it is smaller than the sum of its proper divisors (25784152).

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

21271208 is a wasteful number, since it uses less digits than its factorization.

21271208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12297 (or 12293 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 21271208 is about 4612.0719855614. The cubic root of 21271208 is about 277.0750273551.

The spelling of 21271208 in words is "twenty-one million, two hundred seventy-one thousand, two hundred eight".