21101266 has 16 divisors (see below), whose sum is σ = 32848128. Its totient is φ = 10155600.

The previous prime is 21101263. The next prime is 21101273. The reversal of 21101266 is 66210112.

It is not an unprimeable number, because it can be changed into a prime (21101263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12276 + ... + 13888.

It is an arithmetic number, because the mean of its divisors is an integer number (2053008).

Almost surely, 2^21101266 is an apocalyptic number.

21101266 is a deficient number, since it is larger than the sum of its proper divisors (11746862).

21101266 is a wasteful number, since it uses less digits than its factorization.

21101266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1857.

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

The square root of 21101266 is about 4593.6114332843. The cubic root of 21101266 is about 276.3351753079.

Adding to 21101266 its reverse (66210112), we get a palindrome (87311378).

The spelling of 21101266 in words is "twenty-one million, one hundred one thousand, two hundred sixty-six".