21007266 has 16 divisors (see below), whose sum is σ = 48016704. Its totient is φ = 6002064.

The previous prime is 21007253. The next prime is 21007289. The reversal of 21007266 is 66270012.

It is a happy number.

It is a super-3 number, since 3×21007266³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 250045 + ... + 250128.

It is an arithmetic number, because the mean of its divisors is an integer number (3001044).

Almost surely, 2^21007266 is an apocalyptic number.

21007266 is an abundant number, since it is smaller than the sum of its proper divisors (27009438).

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

21007266 is a wasteful number, since it uses less digits than its factorization.

21007266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500185.

The product of its (nonzero) digits is 1008, while the sum is 24.

The square root of 21007266 is about 4583.3684119870. The cubic root of 21007266 is about 275.9242335611.

Adding to 21007266 its reverse (66270012), we get a palindrome (87277278).

The spelling of 21007266 in words is "twenty-one million, seven thousand, two hundred sixty-six".