21204784925 has 24 divisors (see below), whose sum is σ = 26742431232. Its totient is φ = 16674840000.

The previous prime is 21204784907. The next prime is 21204784943. The reversal of 21204784925 is 52948740212.

It is an interprime number because it is at equal distance from previous prime (21204784907) and next prime (21204784943).

It is not a de Polignac number, because 21204784925 - 2³² = 16909817629 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2971712 + ... + 2978838.

It is an arithmetic number, because the mean of its divisors is an integer number (1114267968).

Almost surely, 2^21204784925 is an apocalyptic number.

21204784925 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21204784925 is a deficient number, since it is larger than the sum of its proper divisors (5537646307).

21204784925 is a wasteful number, since it uses less digits than its factorization.

21204784925 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9149 (or 9144 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 44.

The spelling of 21204784925 in words is "twenty-one billion, two hundred four million, seven hundred eighty-four thousand, nine hundred twenty-five".