1215981312 has 288 divisors, whose sum is σ = 4043784192. Its totient is φ = 315850752.

The previous prime is 1215981311. The next prime is 1215981317. The reversal of 1215981312 is 2131895121.

It is a super-2 number, since 2×1215981312² = 2957221102266482688, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215981311) 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, 8875708 + ... + 8875844.

Almost surely, 2^1215981312 is an apocalyptic number.

1215981312 is a gapful number since it is divisible by the number (12) 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 1215981312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2021892096).

1215981312 is an abundant number, since it is smaller than the sum of its proper divisors (2827802880).

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

1215981312 is a wasteful number, since it uses less digits than its factorization.

1215981312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 303 (or 289 counting only the distinct ones).

The product of its digits is 4320, while the sum is 33.

The square root of 1215981312 is about 34870.9235897187. The cubic root of 1215981312 is about 1067.3551915781.

The spelling of 1215981312 in words is "one billion, two hundred fifteen million, nine hundred eighty-one thousand, three hundred twelve".