1982168721 has 36 divisors (see below), whose sum is σ = 3172520208. Its totient is φ = 1191389472.

The previous prime is 1982168717. The next prime is 1982168723. The reversal of 1982168721 is 1278612891.

It is not a de Polignac number, because 1982168721 - 2² = 1982168717 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1982168723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 50250 + ... + 80556.

Almost surely, 2^1982168721 is an apocalyptic number.

It is an amenable number.

1982168721 is a deficient number, since it is larger than the sum of its proper divisors (1190351487).

1982168721 is a wasteful number, since it uses less digits than its factorization.

1982168721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30382 (or 30366 counting only the distinct ones).

The product of its digits is 96768, while the sum is 45.

The square root of 1982168721 is about 44521.5534432481. The cubic root of 1982168721 is about 1256.1655327777.

The spelling of 1982168721 in words is "one billion, nine hundred eighty-two million, one hundred sixty-eight thousand, seven hundred twenty-one".