12991236 has 12 divisors (see below), whose sum is σ = 30312912. Its totient is φ = 4330408.

The previous prime is 12991229. The next prime is 12991249. The reversal of 12991236 is 63219921.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 12991197 and 12991206.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 541290 + ... + 541313.

It is an arithmetic number, because the mean of its divisors is an integer number (2526076).

Almost surely, 2^12991236 is an apocalyptic number.

It is an amenable number.

12991236 is an abundant number, since it is smaller than the sum of its proper divisors (17321676).

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

12991236 is a wasteful number, since it uses less digits than its factorization.

12991236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1082610 (or 1082608 counting only the distinct ones).

The product of its digits is 5832, while the sum is 33.

The square root of 12991236 is about 3604.3357224321. The cubic root of 12991236 is about 235.0806181830.

The spelling of 12991236 in words is "twelve million, nine hundred ninety-one thousand, two hundred thirty-six".