1215545216 has 128 divisors (see below), whose sum is σ = 2749593600. Its totient is φ = 532224000.

The previous prime is 1215545213. The next prime is 1215545249. The reversal of 1215545216 is 6125455121.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215545213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1733666 + ... + 1734366.

It is an arithmetic number, because the mean of its divisors is an integer number (21481200).

Almost surely, 2^1215545216 is an apocalyptic number.

1215545216 is a gapful number since it is divisible by the number (16) 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 1215545216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1374796800).

1215545216 is an abundant number, since it is smaller than the sum of its proper divisors (1534048384).

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

1215545216 is a wasteful number, since it uses less digits than its factorization.

1215545216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788 (or 776 counting only the distinct ones).

The product of its digits is 12000, while the sum is 32.

The square root of 1215545216 is about 34864.6700256865. The cubic root of 1215545216 is about 1067.2275786011.

The spelling of 1215545216 in words is "one billion, two hundred fifteen million, five hundred forty-five thousand, two hundred sixteen".