1215644616625 has 8 divisors (see below), whose sum is σ = 1517124481704. Its totient is φ = 972515693200.

The previous prime is 1215644616623. The next prime is 1215644616631. The reversal of 1215644616625 is 5266164465121.

It can be written as a sum of positive squares in 4 ways, for example, as 70061854864 + 1145582761761 = 264692^2 + 1070319^2 .

It is not a de Polignac number, because 1215644616625 - 2¹ = 1215644616623 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1215644616623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4862578342 + ... + 4862578591.

It is an arithmetic number, because the mean of its divisors is an integer number (189640560213).

Almost surely, 2^{1215644616625} is an apocalyptic number.

It is an amenable number.

1215644616625 is a deficient number, since it is larger than the sum of its proper divisors (301479865079).

1215644616625 is an frugal number, since it uses more digits than its factorization.

1215644616625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9725156948 (or 9725156938 counting only the distinct ones).

The product of its digits is 2073600, while the sum is 49.

The spelling of 1215644616625 in words is "one trillion, two hundred fifteen billion, six hundred forty-four million, six hundred sixteen thousand, six hundred twenty-five".