9781321672 has 16 divisors (see below), whose sum is σ = 18356866560. Its totient is φ = 4886157264.

The previous prime is 9781321651. The next prime is 9781321681. The reversal of 9781321672 is 2761231879.

It is a super-2 number, since 2×9781321672² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 553708 + ... + 571099.

It is an arithmetic number, because the mean of its divisors is an integer number (1147304160).

Almost surely, 2^9781321672 is an apocalyptic number.

It is an amenable number.

9781321672 is a deficient number, since it is larger than the sum of its proper divisors (8575544888).

9781321672 is a wasteful number, since it uses less digits than its factorization.

9781321672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1125900 (or 1125896 counting only the distinct ones).

The product of its digits is 254016, while the sum is 46.

The square root of 9781321672 is about 98900.5645686616. The cubic root of 9781321672 is about 2138.6145333912.

The spelling of 9781321672 in words is "nine billion, seven hundred eighty-one million, three hundred twenty-one thousand, six hundred seventy-two".