1215765564 has 96 divisors (see below), whose sum is σ = 3207751680. Its totient is φ = 355795200.

The previous prime is 1215765541. The next prime is 1215765599. The reversal of 1215765564 is 4655675121.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 283194 + ... + 287454.

It is an arithmetic number, because the mean of its divisors is an integer number (33414080).

Almost surely, 2^1215765564 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1215765564, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1603875840).

1215765564 is an abundant number, since it is smaller than the sum of its proper divisors (1991986116).

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

1215765564 is a wasteful number, since it uses less digits than its factorization.

1215765564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4371 (or 4369 counting only the distinct ones).

The product of its digits is 252000, while the sum is 42.

The square root of 1215765564 is about 34867.8299296070. The cubic root of 1215765564 is about 1067.2920619433.

The spelling of 1215765564 in words is "one billion, two hundred fifteen million, seven hundred sixty-five thousand, five hundred sixty-four".