3121115430505 has 4 divisors (see below), whose sum is σ = 3745338516612. Its totient is φ = 2496892344400.

The previous prime is 3121115430467. The next prime is 3121115430509. The reversal of 3121115430505 is 5050345111213.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1895542443369 + 1225572987136 = 1376787^2 + 1107056^2 .

It is not a de Polignac number, because 3121115430505 - 2¹⁵ = 3121115397737 is a prime.

It is a super-2 number, since 2×3121115430505² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3121115430509) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312111543046 + ... + 312111543055.

It is an arithmetic number, because the mean of its divisors is an integer number (936334629153).

Almost surely, 2^{3121115430505} is an apocalyptic number.

It is an amenable number.

3121115430505 is a deficient number, since it is larger than the sum of its proper divisors (624223086107).

3121115430505 is an equidigital number, since it uses as much as digits as its factorization.

3121115430505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624223086106.

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

The spelling of 3121115430505 in words is "three trillion, one hundred twenty-one billion, one hundred fifteen million, four hundred thirty thousand, five hundred five".