1215326665 has 24 divisors (see below), whose sum is σ = 1698071040. Its totient is φ = 832593888.

The previous prime is 1215326657. The next prime is 1215326683. The reversal of 1215326665 is 5666235121.

It is not a de Polignac number, because 1215326665 - 2³ = 1215326657 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 420696 + ... + 423574.

It is an arithmetic number, because the mean of its divisors is an integer number (70752960).

Almost surely, 2^1215326665 is an apocalyptic number.

It is an amenable number.

1215326665 is a deficient number, since it is larger than the sum of its proper divisors (482744375).

1215326665 is a wasteful number, since it uses less digits than its factorization.

1215326665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4621 (or 4614 counting only the distinct ones).

The product of its digits is 64800, while the sum is 37.

The square root of 1215326665 is about 34861.5356087479. The cubic root of 1215326665 is about 1067.1636134405.

The spelling of 1215326665 in words is "one billion, two hundred fifteen million, three hundred twenty-six thousand, six hundred sixty-five".