21210104 has 16 divisors (see below), whose sum is σ = 39818520. Its totient is φ = 10591840.

The previous prime is 21210103. The next prime is 21210109. The reversal of 21210104 is 40101212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210103) 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 3 ways as a sum of consecutive naturals, for example, 10019 + ... + 11949.

Almost surely, 2^21210104 is an apocalyptic number.

It is an amenable number.

21210104 is a deficient number, since it is larger than the sum of its proper divisors (18608416).

21210104 is a wasteful number, since it uses less digits than its factorization.

21210104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3310 (or 3306 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21210104 is about 4605.4428668696. The cubic root of 21210104 is about 276.8094629061.

Adding to 21210104 its reverse (40101212), we get a palindrome (61311316).

The spelling of 21210104 in words is "twenty-one million, two hundred ten thousand, one hundred four".