12991776 has 48 divisors (see below), whose sum is σ = 38977344. Its totient is φ = 3711744.

The previous prime is 12991753. The next prime is 12991777. The reversal of 12991776 is 67719921.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is not an unprimeable number, because it can be changed into a prime (12991777) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8995 + ... + 10338.

It is an arithmetic number, because the mean of its divisors is an integer number (812028).

Almost surely, 2^12991776 is an apocalyptic number.

12991776 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

12991776 is an abundant number, since it is smaller than the sum of its proper divisors (25985568).

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

12991776 is a wasteful number, since it uses less digits than its factorization.

12991776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19353 (or 19345 counting only the distinct ones).

The product of its digits is 47628, while the sum is 42.

The square root of 12991776 is about 3604.4106314348. The cubic root of 12991776 is about 235.0838752961.

The spelling of 12991776 in words is "twelve million, nine hundred ninety-one thousand, seven hundred seventy-six".