13235721 has 8 divisors (see below), whose sum is σ = 17665440. Its totient is φ = 8814912.

The previous prime is 13235713. The next prime is 13235731. The reversal of 13235721 is 12753231.

13235721 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 13235721 - 2³ = 13235713 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13235691 and 13235700.

It is not an unprimeable number, because it can be changed into a prime (13235731) 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, 2986 + ... + 5948.

It is an arithmetic number, because the mean of its divisors is an integer number (2208180).

Almost surely, 2^13235721 is an apocalyptic number.

It is an amenable number.

13235721 is a deficient number, since it is larger than the sum of its proper divisors (4429719).

13235721 is a wasteful number, since it uses less digits than its factorization.

13235721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4455.

The product of its digits is 1260, while the sum is 24.

The square root of 13235721 is about 3638.0930444396. The cubic root of 13235721 is about 236.5461413249.

Adding to 13235721 its reverse (12753231), we get a palindrome (25988952).

It can be divided in two parts, 132 and 35721, that added together give a palindrome (35853).

The spelling of 13235721 in words is "thirteen million, two hundred thirty-five thousand, seven hundred twenty-one".