21200104 has 8 divisors (see below), whose sum is σ = 39750210. Its totient is φ = 10600048.

The previous prime is 21200093. The next prime is 21200117. The reversal of 21200104 is 40100212.

It can be written as a sum of positive squares in only one way, i.e., 19377604 + 1822500 = 4402^2 + 1350^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a super-2 number, since 2×21200104² = 898888819221632, which contains 22 as substring.

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, 1324999 + ... + 1325014.

Almost surely, 2^21200104 is an apocalyptic number.

It is an amenable number.

21200104 is a deficient number, since it is larger than the sum of its proper divisors (18550106).

21200104 is a wasteful number, since it uses less digits than its factorization.

21200104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650019 (or 2650015 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21200104 is about 4604.3570669530. The cubic root of 21200104 is about 276.7659533007.

Adding to 21200104 its reverse (40100212), we get a palindrome (61300316).

The spelling of 21200104 in words is "twenty-one million, two hundred thousand, one hundred four".