12432721 has 16 divisors (see below), whose sum is σ = 14742400. Its totient is φ = 10478160.

The previous prime is 12432713. The next prime is 12432731. The reversal of 12432721 is 12723421.

It is not a de Polignac number, because 12432721 - 2³ = 12432713 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12432692 and 12432701.

It is not an unprimeable number, because it can be changed into a prime (12432701) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22711 + ... + 23251.

It is an arithmetic number, because the mean of its divisors is an integer number (921400).

Almost surely, 2^12432721 is an apocalyptic number.

It is an amenable number.

12432721 is a deficient number, since it is larger than the sum of its proper divisors (2309679).

12432721 is an frugal number, since it uses more digits than its factorization.

12432721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629 (or 615 counting only the distinct ones).

The product of its digits is 672, while the sum is 22.

The square root of 12432721 is about 3526.0063811627. The cubic root of 12432721 is about 231.6623171437.

The spelling of 12432721 in words is "twelve million, four hundred thirty-two thousand, seven hundred twenty-one".