1988971475481 has 45 divisors (see below), whose sum is σ = 2986368535821. Its totient is φ = 1319236886016.

The previous prime is 1988971475459. The next prime is 1988971475483. The reversal of 1988971475481 is 1845741798891.

The square root of 1988971475481 is 1410309.

It is a perfect power (a square), and thus also a powerful number.

1988971475481 is a `hidden beast` number, since 1 + 9 + 8 + 8 + 9 + 71 + 4 + 7 + 548 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 241023065481 + 1747948410000 = 490941^2 + 1322100^2 .

It is not a de Polignac number, because 1988971475481 - 2¹⁹ = 1988970951193 is a prime.

It is a super-2 number, since 2×1988971475481² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1988971475483) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 4429780345 + ... + 4429780793.

Almost surely, 2^{1988971475481} is an apocalyptic number.

1988971475481 is the 1410309-th square number.

1988971475481 is the 705155-th centered octagonal number.

It is an amenable number.

1988971475481 is a deficient number, since it is larger than the sum of its proper divisors (997397060340).

1988971475481 is an frugal number, since it uses more digits than its factorization.

1988971475481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1608 (or 801 counting only the distinct ones).

The product of its digits is 162570240, while the sum is 72.

The spelling of 1988971475481 in words is "one trillion, nine hundred eighty-eight billion, nine hundred seventy-one million, four hundred seventy-five thousand, four hundred eighty-one".