6315721 has 4 divisors (see below), whose sum is σ = 6687252. Its totient is φ = 5944192.

The previous prime is 6315713. The next prime is 6315737. The reversal of 6315721 is 1275136.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5707321 + 608400 = 2389^2 + 780^2 .

It is a cyclic number.

It is not a de Polignac number, because 6315721 - 2³ = 6315713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6315781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 185740 + ... + 185773.

It is an arithmetic number, because the mean of its divisors is an integer number (1671813).

Almost surely, 2^6315721 is an apocalyptic number.

It is an amenable number.

6315721 is a deficient number, since it is larger than the sum of its proper divisors (371531).

6315721 is a wasteful number, since it uses less digits than its factorization.

6315721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371530.

The product of its digits is 1260, while the sum is 25.

The square root of 6315721 is about 2513.1098264899. The cubic root of 6315721 is about 184.8449736091.

The spelling of 6315721 in words is "six million, three hundred fifteen thousand, seven hundred twenty-one".