1216507776 has 128 divisors (see below), whose sum is σ = 3647030400. Its totient is φ = 355891200.

The previous prime is 1216507763. The next prime is 1216507783. The reversal of 1216507776 is 6777056121.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 117531 + ... + 127461.

It is an arithmetic number, because the mean of its divisors is an integer number (28492425).

Almost surely, 2^1216507776 is an apocalyptic number.

1216507776 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 1216507776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1823515200).

1216507776 is an abundant number, since it is smaller than the sum of its proper divisors (2430522624).

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

1216507776 is a wasteful number, since it uses less digits than its factorization.

1216507776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9988 (or 9976 counting only the distinct ones).

The product of its (nonzero) digits is 123480, while the sum is 42.

The square root of 1216507776 is about 34878.4715261435. The cubic root of 1216507776 is about 1067.5092079273.

The spelling of 1216507776 in words is "one billion, two hundred sixteen million, five hundred seven thousand, seven hundred seventy-six".