315621281 has 2 divisors, whose sum is σ = 315621282. Its totient is φ = 315621280.

The previous prime is 315621277. The next prime is 315621329. The reversal of 315621281 is 182126513.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 185204881 + 130416400 = 13609^2 + 11420^2 .

It is a cyclic number.

It is not a de Polignac number, because 315621281 - 2² = 315621277 is a prime.

It is a super-2 number, since 2×315621281² = 199233586040161922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (315621221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157810640 + 157810641.

It is an arithmetic number, because the mean of its divisors is an integer number (157810641).

Almost surely, 2^315621281 is an apocalyptic number.

It is an amenable number.

315621281 is a deficient number, since it is larger than the sum of its proper divisors (1).

315621281 is an equidigital number, since it uses as much as digits as its factorization.

315621281 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2880, while the sum is 29.

The square root of 315621281 is about 17765.7333369608. The cubic root of 315621281 is about 680.8562462016.

Adding to 315621281 its reverse (182126513), we get a palindrome (497747794).

The spelling of 315621281 in words is "three hundred fifteen million, six hundred twenty-one thousand, two hundred eighty-one".