1215156600 has 768 divisors, whose sum is σ = 5313945600. Its totient is φ = 248832000.

The previous prime is 1215156589. The next prime is 1215156641. The reversal of 1215156600 is 66515121.

It is a happy number.

1215156600 is a `hidden beast` number, since 1 + 2 + 1 + 5 + 1 + 56 + 600 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 19920570 + ... + 19920630.

It is an arithmetic number, because the mean of its divisors is an integer number (6919200).

Almost surely, 2^1215156600 is an apocalyptic number.

1215156600 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 1215156600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2656972800).

1215156600 is an abundant number, since it is smaller than the sum of its proper divisors (4098789000).

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

1215156600 is a wasteful number, since it uses less digits than its factorization.

1215156600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141 (or 126 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 1215156600 is about 34859.0963738305. The cubic root of 1215156600 is about 1067.1138337801.

The spelling of 1215156600 in words is "one billion, two hundred fifteen million, one hundred fifty-six thousand, six hundred".