21207276 has 36 divisors (see below), whose sum is σ = 54217800. Its totient is φ = 6988608.

The previous prime is 21207271. The next prime is 21207301. The reversal of 21207276 is 67270212.

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (21207271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 106 + ... + 6513.

It is an arithmetic number, because the mean of its divisors is an integer number (1506050).

Almost surely, 2^21207276 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21207276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27108900).

21207276 is an abundant number, since it is smaller than the sum of its proper divisors (33010524).

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

21207276 is a wasteful number, since it uses less digits than its factorization.

21207276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6718 (or 6713 counting only the distinct ones).

The product of its (nonzero) digits is 2352, while the sum is 27.

The square root of 21207276 is about 4605.1358286157. The cubic root of 21207276 is about 276.7971597768.

Adding to 21207276 its reverse (67270212), we get a palindrome (88477488).

The spelling of 21207276 in words is "twenty-one million, two hundred seven thousand, two hundred seventy-six".