315821201 has 2 divisors, whose sum is σ = 315821202. Its totient is φ = 315821200.

The previous prime is 315821171. The next prime is 315821221. The reversal of 315821201 is 102128513.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209236225 + 106584976 = 14465^2 + 10324^2 .

It is an emirp because it is prime and its reverse (102128513) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-315821201 is a prime.

It is a Chen prime.

It is equal to p_17062007 and since 315821201 and 17062007 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (315821221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157910600 + 157910601.

It is an arithmetic number, because the mean of its divisors is an integer number (157910601).

Almost surely, 2^315821201 is an apocalyptic number.

It is an amenable number.

315821201 is a deficient number, since it is larger than the sum of its proper divisors (1).

315821201 is an equidigital number, since it uses as much as digits as its factorization.

315821201 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 315821201 is about 17771.3590082469. The cubic root of 315821201 is about 680.9999712496. Note that the first 4 decimals are identical.

Adding to 315821201 its reverse (102128513), we get a palindrome (417949714).

The spelling of 315821201 in words is "three hundred fifteen million, eight hundred twenty-one thousand, two hundred one".