21221104 has 10 divisors (see below), whose sum is σ = 41115920. Its totient is φ = 10610544.

The previous prime is 21221099. The next prime is 21221113. The reversal of 21221104 is 40112212.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 663144 + ... + 663175.

It is an arithmetic number, because the mean of its divisors is an integer number (4111592).

Almost surely, 2^21221104 is an apocalyptic number.

It is an amenable number.

21221104 is a deficient number, since it is larger than the sum of its proper divisors (19894816).

21221104 is a wasteful number, since it uses less digits than its factorization.

21221104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1326327 (or 1326321 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 21221104 is about 4606.6369511825. The cubic root of 21221104 is about 276.8573076796.

Adding to 21221104 its reverse (40112212), we get a palindrome (61333316).

It can be divided in two parts, 212 and 21104, that added together give a square (21316 = 146²).

The spelling of 21221104 in words is "twenty-one million, two hundred twenty-one thousand, one hundred four".