1981008773 has 8 divisors (see below), whose sum is σ = 1993836768. Its totient is φ = 1968222384.

The previous prime is 1981008769. The next prime is 1981008829. The reversal of 1981008773 is 3778001891.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1981008773 - 2² = 1981008769 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1981008703) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88115 + ... + 108287.

It is an arithmetic number, because the mean of its divisors is an integer number (249229596).

Almost surely, 2^1981008773 is an apocalyptic number.

It is an amenable number.

1981008773 is a deficient number, since it is larger than the sum of its proper divisors (12827995).

1981008773 is a wasteful number, since it uses less digits than its factorization.

1981008773 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20803.

The product of its (nonzero) digits is 84672, while the sum is 44.

The square root of 1981008773 is about 44508.5247227989. The cubic root of 1981008773 is about 1255.9204525618.

The spelling of 1981008773 in words is "one billion, nine hundred eighty-one million, eight thousand, seven hundred seventy-three".