21204110104 has 8 divisors (see below), whose sum is σ = 39757706460. Its totient is φ = 10602055048.

The previous prime is 21204110099. The next prime is 21204110117. The reversal of 21204110104 is 40101140212.

It is a happy number.

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

It is a super-2 number, since 2×21204110104² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1325256874 + ... + 1325256889.

Almost surely, 2^21204110104 is an apocalyptic number.

It is an amenable number.

21204110104 is a deficient number, since it is larger than the sum of its proper divisors (18553596356).

21204110104 is a wasteful number, since it uses less digits than its factorization.

21204110104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2650513769 (or 2650513765 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21204110104 its reverse (40101140212), we get a palindrome (61305250316).

The spelling of 21204110104 in words is "twenty-one billion, two hundred four million, one hundred ten thousand, one hundred four".