316687721 has 8 divisors (see below), whose sum is σ = 365996160. Its totient is φ = 268396128.

The previous prime is 316687703. The next prime is 316687757. The reversal of 316687721 is 127786613.

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

It is a de Polignac number, because none of the positive numbers 2^k-316687721 is a prime.

It is a super-2 number, since 2×316687721² = 200582225264347682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (316683721) 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, 253541 + ... + 254786.

It is an arithmetic number, because the mean of its divisors is an integer number (45749520).

Almost surely, 2^316687721 is an apocalyptic number.

It is an amenable number.

316687721 is a deficient number, since it is larger than the sum of its proper divisors (49308439).

316687721 is an equidigital number, since it uses as much as digits as its factorization.

316687721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 508423.

The product of its digits is 84672, while the sum is 41.

The square root of 316687721 is about 17795.7219859156. The cubic root of 316687721 is about 681.6222233631.

The spelling of 316687721 in words is "three hundred sixteen million, six hundred eighty-seven thousand, seven hundred twenty-one".