315601921 has 4 divisors (see below), whose sum is σ = 319148100. Its totient is φ = 312055744.

The previous prime is 315601907. The next prime is 315601931. The reversal of 315601921 is 129106513.

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 223921296 + 91680625 = 14964^2 + 9575^2 .

It is a cyclic number.

It is not a de Polignac number, because 315601921 - 2¹¹ = 315599873 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 315601921.

It is not an unprimeable number, because it can be changed into a prime (315601901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1772956 + ... + 1773133.

It is an arithmetic number, because the mean of its divisors is an integer number (79787025).

Almost surely, 2^315601921 is an apocalyptic number.

It is an amenable number.

315601921 is a deficient number, since it is larger than the sum of its proper divisors (3546179).

315601921 is an equidigital number, since it uses as much as digits as its factorization.

315601921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3546178.

The product of its (nonzero) digits is 1620, while the sum is 28.

The square root of 315601921 is about 17765.1884594563. The cubic root of 315601921 is about 680.8423248268.

The spelling of 315601921 in words is "three hundred fifteen million, six hundred one thousand, nine hundred twenty-one".