981921906625 has 16 divisors (see below), whose sum is σ = 1336842044928. Its totient is φ = 714125022000.

The previous prime is 981921906599. The next prime is 981921906629. The reversal of 981921906625 is 526609129189.

It is not a de Polignac number, because 981921906625 - 2²⁹ = 981385035713 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 981921906625.

It is not an unprimeable number, because it can be changed into a prime (981921906629) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 357061137 + ... + 357063886.

It is an arithmetic number, because the mean of its divisors is an integer number (83552627808).

Almost surely, 2^981921906625 is an apocalyptic number.

It is an amenable number.

981921906625 is a deficient number, since it is larger than the sum of its proper divisors (354920138303).

981921906625 is a wasteful number, since it uses less digits than its factorization.

981921906625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 714125049 (or 714125039 counting only the distinct ones).

The product of its (nonzero) digits is 4199040, while the sum is 58.

The spelling of 981921906625 in words is "nine hundred eighty-one billion, nine hundred twenty-one million, nine hundred six thousand, six hundred twenty-five".