1981938585625 has 20 divisors (see below), whose sum is σ = 2483097154560. Its totient is φ = 1581410858000.

The previous prime is 1981938585617. The next prime is 1981938585629. The reversal of 1981938585625 is 5265858391891.

It is not a de Polignac number, because 1981938585625 - 2³ = 1981938585617 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1981938585629) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 3900445 + ... + 4379194.

It is an arithmetic number, because the mean of its divisors is an integer number (124154857728).

Almost surely, 2^{1981938585625} is an apocalyptic number.

It is an amenable number.

1981938585625 is a deficient number, since it is larger than the sum of its proper divisors (501158568935).

1981938585625 is an frugal number, since it uses more digits than its factorization.

1981938585625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8280042 (or 8280027 counting only the distinct ones).

The product of its digits is 186624000, while the sum is 70.

The spelling of 1981938585625 in words is "one trillion, nine hundred eighty-one billion, nine hundred thirty-eight million, five hundred eighty-five thousand, six hundred twenty-five".