1981763289 has 81 divisors (see below), whose sum is σ = 3368183637. Its totient is φ = 1121828400.

The previous prime is 1981763281. The next prime is 1981763293. The reversal of 1981763289 is 9823671891.

The square root of 1981763289 is 44517.

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

1981763289 is a `hidden beast` number, since 198 + 176 + 3 + 289 = 666.

It is not a de Polignac number, because 1981763289 - 2³ = 1981763281 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1981763281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 27912124 + ... + 27912194.

Almost surely, 2^1981763289 is an apocalyptic number.

1981763289 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1981763289 is the 44517-th square number.

1981763289 is the 22259-th centered octagonal number.

It is an amenable number.

1981763289 is a deficient number, since it is larger than the sum of its proper divisors (1386420348).

1981763289 is a wasteful number, since it uses less digits than its factorization.

1981763289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 208 (or 104 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 54.

The cubic root of 1981763289 is about 1256.0798817387.

The spelling of 1981763289 in words is "one billion, nine hundred eighty-one million, seven hundred sixty-three thousand, two hundred eighty-nine".