1215328920 has 256 divisors, whose sum is σ = 4177958400. Its totient is φ = 280350720.

The previous prime is 1215328903. The next prime is 1215328921. The reversal of 1215328920 is 298235121.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215328921) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3882684 + ... + 3882996.

It is an arithmetic number, because the mean of its divisors is an integer number (16320150).

Almost surely, 2^1215328920 is an apocalyptic number.

1215328920 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 1215328920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2088979200).

1215328920 is an abundant number, since it is smaller than the sum of its proper divisors (2962629480).

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

1215328920 is a wasteful number, since it uses less digits than its factorization.

1215328920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 490 (or 486 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 33.

The square root of 1215328920 is about 34861.5679509686. The cubic root of 1215328920 is about 1067.1642734695.

The spelling of 1215328920 in words is "one billion, two hundred fifteen million, three hundred twenty-eight thousand, nine hundred twenty".