21011266 has 8 divisors (see below), whose sum is σ = 31607244. Its totient is φ = 10475520.

The previous prime is 21011251. The next prime is 21011293. The reversal of 21011266 is 66211012.

It can be written as a sum of positive squares in 2 ways, for example, as 19847025 + 1164241 = 4455^2 + 1079^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

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, 14175 + ... + 15586.

Almost surely, 2^21011266 is an apocalyptic number.

21011266 is a deficient number, since it is larger than the sum of its proper divisors (10595978).

21011266 is a wasteful number, since it uses less digits than its factorization.

21011266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30116.

The product of its (nonzero) digits is 144, while the sum is 19.

The square root of 21011266 is about 4583.8047515137. The cubic root of 21011266 is about 275.9417453892.

Adding to 21011266 its reverse (66211012), we get a palindrome (87222278).

It can be divided in two parts, 210 and 11266, that added together give a triangular number (11476 = T₁₅₁).

The spelling of 21011266 in words is "twenty-one million, eleven thousand, two hundred sixty-six".