1216601680 has 80 divisors (see below), whose sum is σ = 3252291840. Its totient is φ = 414590976.

The previous prime is 1216601677. The next prime is 1216601681. The reversal of 1216601680 is 861066121.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216601681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 87016 + ... + 100024.

It is an arithmetic number, because the mean of its divisors is an integer number (40653648).

Almost surely, 2^1216601680 is an apocalyptic number.

1216601680 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 1216601680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1626145920).

1216601680 is an abundant number, since it is smaller than the sum of its proper divisors (2035690160).

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

1216601680 is a wasteful number, since it uses less digits than its factorization.

1216601680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13196 (or 13190 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 31.

The square root of 1216601680 is about 34879.8176600739. The cubic root of 1216601680 is about 1067.5366747488.

The spelling of 1216601680 in words is "one billion, two hundred sixteen million, six hundred one thousand, six hundred eighty".