1215100800 has 288 divisors, whose sum is σ = 4478909760. Its totient is φ = 313344000.

The previous prime is 1215100771. The next prime is 1215100807. The reversal of 1215100800 is 80015121.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215100807) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 892120 + ... + 893480.

It is an arithmetic number, because the mean of its divisors is an integer number (15551770).

Almost surely, 2^1215100800 is an apocalyptic number.

1215100800 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 1215100800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2239454880).

1215100800 is an abundant number, since it is smaller than the sum of its proper divisors (3263808960).

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

1215100800 is a wasteful number, since it uses less digits than its factorization.

1215100800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1422 (or 1402 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 1215100800 is about 34858.2959996613. The cubic root of 1215100800 is about 1067.0974995718.

Adding to 1215100800 its reverse (80015121), we get a palindrome (1295115921).

The spelling of 1215100800 in words is "one billion, two hundred fifteen million, one hundred thousand, eight hundred".