315101221 has 2 divisors, whose sum is σ = 315101222. Its totient is φ = 315101220.

The previous prime is 315101209. The next prime is 315101231. The reversal of 315101221 is 122101513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 303804900 + 11296321 = 17430^2 + 3361^2 .

It is a cyclic number.

It is not a de Polignac number, because 315101221 - 2²⁵ = 281546789 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 315101195 and 315101204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (315101231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 157550610 + 157550611.

It is an arithmetic number, because the mean of its divisors is an integer number (157550611).

Almost surely, 2^315101221 is an apocalyptic number.

It is an amenable number.

315101221 is a deficient number, since it is larger than the sum of its proper divisors (1).

315101221 is an equidigital number, since it uses as much as digits as its factorization.

315101221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 315101221 is about 17751.0906988838. The cubic root of 315101221 is about 680.4820838971.

Adding to 315101221 its reverse (122101513), we get a palindrome (437202734).

The spelling of 315101221 in words is "three hundred fifteen million, one hundred one thousand, two hundred twenty-one".