1215951984 has 120 divisors (see below), whose sum is σ = 3691899120. Its totient is φ = 371367936.

The previous prime is 1215951983. The next prime is 1215952037. The reversal of 1215951984 is 4891595121.

1215951984 is a `hidden beast` number, since 1 + 2 + 1 + 59 + 519 + 84 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1215951983) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 257872 + ... + 262544.

It is an arithmetic number, because the mean of its divisors is an integer number (30765826).

Almost surely, 2^1215951984 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 1215951984, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1845949560).

1215951984 is an abundant number, since it is smaller than the sum of its proper divisors (2475947136).

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

1215951984 is a wasteful number, since it uses less digits than its factorization.

1215951984 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4839 (or 4830 counting only the distinct ones).

The product of its digits is 129600, while the sum is 45.

The square root of 1215951984 is about 34870.5030649115. The cubic root of 1215951984 is about 1067.3466104032.

The spelling of 1215951984 in words is "one billion, two hundred fifteen million, nine hundred fifty-one thousand, nine hundred eighty-four".