1215506500 has 96 divisors (see below), whose sum is σ = 2929241952. Its totient is φ = 437760000.

The previous prime is 1215506471. The next prime is 1215506521. The reversal of 1215506500 is 56055121.

It can be written as a sum of positive squares in 16 ways, for example, as 1215359044 + 147456 = 34862^2 + 384^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 264220 + ... + 268780.

It is an arithmetic number, because the mean of its divisors is an integer number (30512937).

Almost surely, 2^1215506500 is an apocalyptic number.

1215506500 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 1215506500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1464620976).

1215506500 is an abundant number, since it is smaller than the sum of its proper divisors (1713735452).

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

1215506500 is a wasteful number, since it uses less digits than its factorization.

1215506500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4634 (or 4622 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 25.

The square root of 1215506500 is about 34864.1147887050. The cubic root of 1215506500 is about 1067.2162478224.

The spelling of 1215506500 in words is "one billion, two hundred fifteen million, five hundred six thousand, five hundred".