1216539891424 has 288 divisors, whose sum is σ = 2930799449088. Its totient is φ = 492231168000.

The previous prime is 1216539891397. The next prime is 1216539891481. The reversal of 1216539891424 is 4241989356121.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 610405372 + ... + 610407364.

It is an arithmetic number, because the mean of its divisors is an integer number (10176386976).

Almost surely, 2^{1216539891424} 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 1216539891424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1465399724544).

1216539891424 is an abundant number, since it is smaller than the sum of its proper divisors (1714259557664).

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

1216539891424 is a wasteful number, since it uses less digits than its factorization.

1216539891424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2402 (or 2381 counting only the distinct ones).

The product of its digits is 3732480, while the sum is 55.

The spelling of 1216539891424 in words is "one trillion, two hundred sixteen billion, five hundred thirty-nine million, eight hundred ninety-one thousand, four hundred twenty-four".