1216538480 has 20 divisors (see below), whose sum is σ = 2828452152. Its totient is φ = 486615360.

The previous prime is 1216538473. The next prime is 1216538483. The reversal of 1216538480 is 848356121.

It is a tau number, because it is divible by the number of its divisors (20).

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1216538483) 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 3 ways as a sum of consecutive naturals, for example, 7603286 + ... + 7603445.

Almost surely, 2^1216538480 is an apocalyptic number.

1216538480 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1216538480 is an abundant number, since it is smaller than the sum of its proper divisors (1611913672).

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

1216538480 is a wasteful number, since it uses less digits than its factorization.

1216538480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15206744 (or 15206738 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 38.

The square root of 1216538480 is about 34878.9116802689. The cubic root of 1216538480 is about 1067.5181889706.

The spelling of 1216538480 in words is "one billion, two hundred sixteen million, five hundred thirty-eight thousand, four hundred eighty".