12921472 has 48 divisors (see below), whose sum is σ = 27088650. Its totient is φ = 6132224.

The previous prime is 12921449. The next prime is 12921527. The reversal of 12921472 is 27412921.

It can be written as a sum of positive squares in only one way, i.e., 10916416 + 2005056 = 3304^2 + 1416^2 .

It is an alternating number because its digits alternate between odd and even.

It is a self number, because there is not a number n which added to its sum of digits gives 12921472.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 218979 + ... + 219037.

Almost surely, 2^12921472 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12921472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13544325).

12921472 is an abundant number, since it is smaller than the sum of its proper divisors (14167178).

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

12921472 is an frugal number, since it uses more digits than its factorization.

12921472 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 161 (or 90 counting only the distinct ones).

The product of its digits is 2016, while the sum is 28.

The square root of 12921472 is about 3594.6449059678. The cubic root of 12921472 is about 234.6590619666.

It can be divided in two parts, 129214 and 72, that added together give a triangular number (129286 = T₅₀₈).

The spelling of 12921472 in words is "twelve million, nine hundred twenty-one thousand, four hundred seventy-two".