1215100128 has 192 divisors, whose sum is σ = 3615591168. Its totient is φ = 354078720.

The previous prime is 1215100127. The next prime is 1215100129. The reversal of 1215100128 is 8210015121.

It is an interprime number because it is at equal distance from previous prime (1215100127) and next prime (1215100129).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215100127) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5352751 + ... + 5352977.

It is an arithmetic number, because the mean of its divisors is an integer number (18831204).

Almost surely, 2^1215100128 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 1215100128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1807795584).

1215100128 is an abundant number, since it is smaller than the sum of its proper divisors (2400491040).

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

1215100128 is a wasteful number, since it uses less digits than its factorization.

1215100128 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 417 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 21.

The square root of 1215100128 is about 34858.2863606345. The cubic root of 1215100128 is about 1067.0973028557.

Adding to 1215100128 its reverse (8210015121), we get a palindrome (9425115249).

The spelling of 1215100128 in words is "one billion, two hundred fifteen million, one hundred thousand, one hundred twenty-eight".