1216766880 has 192 divisors, whose sum is σ = 4867188480. Its totient is φ = 278111232.

The previous prime is 1216766869. The next prime is 1216766917. The reversal of 1216766880 is 886676121.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (45).

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 31 ways as a sum of consecutive naturals, for example, 10122 + ... + 50358.

It is an arithmetic number, because the mean of its divisors is an integer number (25349940).

Almost surely, 2^1216766880 is an apocalyptic number.

1216766880 is a gapful number since it is divisible by the number (10) 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 1216766880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2433594240).

1216766880 is an abundant number, since it is smaller than the sum of its proper divisors (3650421600).

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

1216766880 is a wasteful number, since it uses less digits than its factorization.

1216766880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40268 (or 40254 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 45.

The square root of 1216766880 is about 34882.1857113341. The cubic root of 1216766880 is about 1067.5849921451.

The spelling of 1216766880 in words is "one billion, two hundred sixteen million, seven hundred sixty-six thousand, eight hundred eighty".