315145561 has 2 divisors, whose sum is σ = 315145562. Its totient is φ = 315145560.

The previous prime is 315145559. The next prime is 315145577. The reversal of 315145561 is 165541513.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 202891536 + 112254025 = 14244^2 + 10595^2 .

It is a cyclic number.

It is not a de Polignac number, because 315145561 - 2¹ = 315145559 is a prime.

Together with 315145559, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (315145661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157572780 + 157572781.

It is an arithmetic number, because the mean of its divisors is an integer number (157572781).

Almost surely, 2^315145561 is an apocalyptic number.

It is an amenable number.

315145561 is a deficient number, since it is larger than the sum of its proper divisors (1).

315145561 is an equidigital number, since it uses as much as digits as its factorization.

315145561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 9000, while the sum is 31.

The square root of 315145561 is about 17752.3395922904. The cubic root of 315145561 is about 680.5140007949.

The spelling of 315145561 in words is "three hundred fifteen million, one hundred forty-five thousand, five hundred sixty-one".