315521 has 2 divisors, whose sum is σ = 315522. Its totient is φ = 315520.

The previous prime is 315517. The next prime is 315527. The reversal of 315521 is 125513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 297025 + 18496 = 545^2 + 136^2 .

It is a cyclic number.

It is not a de Polignac number, because 315521 - 2² = 315517 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 315521.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (315527) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157760 + 157761.

It is an arithmetic number, because the mean of its divisors is an integer number (157761).

2³¹⁵⁵²¹ is an apocalyptic number.

It is an amenable number.

315521 is a deficient number, since it is larger than the sum of its proper divisors (1).

315521 is an equidigital number, since it uses as much as digits as its factorization.

315521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 150, while the sum is 17.

The square root of 315521 is about 561.7125599450. The cubic root of 315521 is about 68.0784130049.

The spelling of 315521 in words is "three hundred fifteen thousand, five hundred twenty-one".