1215121311145 has 24 divisors (see below), whose sum is σ = 1795987230984. Its totient is φ = 784212742656.

The previous prime is 1215121311139. The next prime is 1215121311163. The reversal of 1215121311145 is 5411131215121.

It can be written as a sum of positive squares in 4 ways, for example, as 426429896256 + 788691414889 = 653016^2 + 888083^2 .

It is not a de Polignac number, because 1215121311145 - 2⁵ = 1215121311113 is a prime.

It is a super-2 number, since 2×1215121311145² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 145868742 + ... + 145877071.

It is an arithmetic number, because the mean of its divisors is an integer number (74832801291).

Almost surely, 2^{1215121311145} is an apocalyptic number.

It is an amenable number.

1215121311145 is a deficient number, since it is larger than the sum of its proper divisors (580865919839).

1215121311145 is a wasteful number, since it uses less digits than its factorization.

1215121311145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 291745849 (or 291745842 counting only the distinct ones).

The product of its digits is 1200, while the sum is 28.

Adding to 1215121311145 its reverse (5411131215121), we get a palindrome (6626252526266).

The spelling of 1215121311145 in words is "one trillion, two hundred fifteen billion, one hundred twenty-one million, three hundred eleven thousand, one hundred forty-five".