1981149146089 has 3 divisors (see below), whose sum is σ = 1981150553623. Its totient is φ = 1981147738556.

The previous prime is 1981149146059. The next prime is 1981149146149. The reversal of 1981149146089 is 9806419411891.

The square root of 1981149146089 is 1407533.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1193152059225 + 787997086864 = 1092315^2 + 887692^2 .

It is not a de Polignac number, because 1981149146089 - 2¹⁹ = 1981148621801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981149146059) 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 2 ways as a sum of consecutive naturals, for example, 703767 + ... + 2111299.

Almost surely, 2^{1981149146089} is an apocalyptic number.

1981149146089 is the 1407533-rd square number.

1981149146089 is the 703767-th centered octagonal number.

It is an amenable number.

1981149146089 is a deficient number, since it is larger than the sum of its proper divisors (1407534).

1981149146089 is an frugal number, since it uses more digits than its factorization.

1981149146089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2815066 (or 1407533 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 61.

The spelling of 1981149146089 in words is "one trillion, nine hundred eighty-one billion, one hundred forty-nine million, one hundred forty-six thousand, eighty-nine".