12991616 has 32 divisors (see below), whose sum is σ = 28237680. Its totient is φ = 5904640.

The previous prime is 12991613. The next prime is 12991661. The reversal of 12991616 is 61619921.

It is a tau number, because it is divible by the number of its divisors (32).

It is not an unprimeable number, because it can be changed into a prime (12991613) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3206 + ... + 6021.

Almost surely, 2^12991616 is an apocalyptic number.

12991616 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

12991616 is an abundant number, since it is smaller than the sum of its proper divisors (15246064).

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

12991616 is an equidigital number, since it uses as much as digits as its factorization.

12991616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9252 (or 9240 counting only the distinct ones).

The product of its digits is 5832, while the sum is 35.

The square root of 12991616 is about 3604.3884363370. The cubic root of 12991616 is about 235.0829102350.

The spelling of 12991616 in words is "twelve million, nine hundred ninety-one thousand, six hundred sixteen".