21103651025 has 12 divisors (see below), whose sum is σ = 27545818800. Its totient is φ = 15994345680.

The previous prime is 21103651013. The next prime is 21103651031. The reversal of 21103651025 is 52015630112.

It is not a de Polignac number, because 21103651025 - 2²⁰ = 21102602449 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21103650985 and 21103651003.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 22213895 + ... + 22214844.

It is an arithmetic number, because the mean of its divisors is an integer number (2295484900).

Almost surely, 2^21103651025 is an apocalyptic number.

21103651025 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21103651025 is a deficient number, since it is larger than the sum of its proper divisors (6442167775).

21103651025 is a wasteful number, since it uses less digits than its factorization.

21103651025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44428768 (or 44428763 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The spelling of 21103651025 in words is "twenty-one billion, one hundred three million, six hundred fifty-one thousand, twenty-five".