12447921 has 8 divisors (see below), whose sum is σ = 16684000. Its totient is φ = 8255232.

The previous prime is 12447901. The next prime is 12447937. The reversal of 12447921 is 12974421.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 12447921 - 2¹⁴ = 12431537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12447901) 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, 10171 + ... + 11328.

It is an arithmetic number, because the mean of its divisors is an integer number (2085500).

Almost surely, 2^12447921 is an apocalyptic number.

It is an amenable number.

12447921 is a deficient number, since it is larger than the sum of its proper divisors (4236079).

12447921 is a wasteful number, since it uses less digits than its factorization.

12447921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21695.

The product of its digits is 4032, while the sum is 30.

The square root of 12447921 is about 3528.1611357760. The cubic root of 12447921 is about 231.7566872923.

The spelling of 12447921 in words is "twelve million, four hundred forty-seven thousand, nine hundred twenty-one".