1215660660 has 192 divisors, whose sum is σ = 3793305600. Its totient is φ = 289612800.

The previous prime is 1215660659. The next prime is 1215660703. The reversal of 1215660660 is 660665121.

It is a super-3 number, since 3×1215660660³ (a number of 28 digits) contains 333 as substring.

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 1448521 + ... + 1449359.

It is an arithmetic number, because the mean of its divisors is an integer number (19756800).

Almost surely, 2^1215660660 is an apocalyptic number.

1215660660 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1215660660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1896652800).

1215660660 is an abundant number, since it is smaller than the sum of its proper divisors (2577644940).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1215660660 is a wasteful number, since it uses less digits than its factorization.

1215660660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942 (or 940 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 1215660660 is about 34866.3255878792. The cubic root of 1215660660 is about 1067.2613634736.

The spelling of 1215660660 in words is "one billion, two hundred fifteen million, six hundred sixty thousand, six hundred sixty".