21104002125 has 24 divisors (see below), whose sum is σ = 38043483192. Its totient is φ = 11255467200.

The previous prime is 21104002099. The next prime is 21104002141. The reversal of 21104002125 is 52120040112.

It can be written as a sum of positive squares in 4 ways, for example, as 6673746249 + 14430255876 = 81693^2 + 120126^2 .

It is not a de Polignac number, because 21104002125 - 2⁸ = 21104001869 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21104002098 and 21104002107.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9378432 + ... + 9380681.

It is an arithmetic number, because the mean of its divisors is an integer number (1585145133).

Almost surely, 2^21104002125 is an apocalyptic number.

21104002125 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21104002125 is a deficient number, since it is larger than the sum of its proper divisors (16939481067).

21104002125 is a wasteful number, since it uses less digits than its factorization.

21104002125 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18759134 (or 18759121 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

Adding to 21104002125 its reverse (52120040112), we get a palindrome (73224042237).

The spelling of 21104002125 in words is "twenty-one billion, one hundred four million, two thousand, one hundred twenty-five".