1981941361 has 3 divisors (see below), whose sum is σ = 1981985881. Its totient is φ = 1981896842.

The previous prime is 1981941359. The next prime is 1981941373. The reversal of 1981941361 is 1631491891.

It is a happy number.

The square root of 1981941361 is 44519.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1631491891 = 5297 ⋅308003.

It is not a de Polignac number, because 1981941361 - 2¹ = 1981941359 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1981941331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 22260 + ... + 66778.

Almost surely, 2^1981941361 is an apocalyptic number.

1981941361 is the 44519-th square number.

1981941361 is the 22260-th centered octagonal number.

It is an amenable number.

1981941361 is a deficient number, since it is larger than the sum of its proper divisors (44520).

1981941361 is an frugal number, since it uses more digits than its factorization.

1981941361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89038 (or 44519 counting only the distinct ones).

The product of its digits is 46656, while the sum is 43.

The cubic root of 1981941361 is about 1256.1175024372.

Multiplying 1981941361 by its product of digits (46656), we get a square (92469456138816 = 9616104²).

The spelling of 1981941361 in words is "one billion, nine hundred eighty-one million, nine hundred forty-one thousand, three hundred sixty-one".