315121115516221 has 8 divisors (see below), whose sum is σ = 365210789814144. Its totient is φ = 266299534238640.

The previous prime is 315121115516173. The next prime is 315121115516239. The reversal of 315121115516221 is 122615511121513.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 315121115516221 - 2¹⁷ = 315121115385149 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (315121115516021) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 317023254550 + ... + 317023255543.

It is an arithmetic number, because the mean of its divisors is an integer number (45651348726768).

Almost surely, 2^{315121115516221} is an apocalyptic number.

It is an amenable number.

315121115516221 is a deficient number, since it is larger than the sum of its proper divisors (50089674297923).

315121115516221 is an equidigital number, since it uses as much as digits as its factorization.

315121115516221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 634046510171.

The product of its digits is 18000, while the sum is 37.

Adding to 315121115516221 its reverse (122615511121513), we get a palindrome (437736626637734).

The spelling of 315121115516221 in words is "three hundred fifteen trillion, one hundred twenty-one billion, one hundred fifteen million, five hundred sixteen thousand, two hundred twenty-one".