1216591376 has 160 divisors (see below), whose sum is σ = 3251958528. Its totient is φ = 425502720.

The previous prime is 1216591333. The next prime is 1216591379. The reversal of 1216591376 is 6731956121.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (1216591379) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 591566 + ... + 593618.

Almost surely, 2^1216591376 is an apocalyptic number.

1216591376 is a gapful number since it is divisible by the number (16) 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 1216591376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1625979264).

1216591376 is an abundant number, since it is smaller than the sum of its proper divisors (2035367152).

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

1216591376 is a wasteful number, since it uses less digits than its factorization.

1216591376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2129 (or 2123 counting only the distinct ones).

The product of its digits is 68040, while the sum is 41.

The square root of 1216591376 is about 34879.6699525669. The cubic root of 1216591376 is about 1067.5336609086.

The spelling of 1216591376 in words is "one billion, two hundred sixteen million, five hundred ninety-one thousand, three hundred seventy-six".