321716681 has 12 divisors (see below), whose sum is σ = 380039760. Its totient is φ = 269970480.

The previous prime is 321716671. The next prime is 321716693. The reversal of 321716681 is 186617123.

It is a de Polignac number, because none of the positive numbers 2^k-321716681 is a prime.

It is a super-2 number, since 2×321716681² = 207003245667311522, which contains 22 as substring.

It is a Smith number, since the sum of its digits (35) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (321716611) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84671 + ... + 88388.

It is an arithmetic number, because the mean of its divisors is an integer number (31669980).

Almost surely, 2^321716681 is an apocalyptic number.

It is an amenable number.

321716681 is a deficient number, since it is larger than the sum of its proper divisors (58323079).

321716681 is a wasteful number, since it uses less digits than its factorization.

321716681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173096 (or 173083 counting only the distinct ones).

The product of its digits is 12096, while the sum is 35.

The square root of 321716681 is about 17936.4623323553. The cubic root of 321716681 is about 685.2113159825.

The spelling of 321716681 in words is "three hundred twenty-one million, seven hundred sixteen thousand, six hundred eighty-one".