13307721 has 32 divisors (see below), whose sum is σ = 21073920. Its totient is φ = 7312896.

The previous prime is 13307689. The next prime is 13307737. The reversal of 13307721 is 12770331.

13307721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 13307721 - 2⁵ = 13307689 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13307691 and 13307700.

It is not an unprimeable number, because it can be changed into a prime (13307761) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 95670 + ... + 95808.

It is an arithmetic number, because the mean of its divisors is an integer number (658560).

Almost surely, 2^13307721 is an apocalyptic number.

It is an amenable number.

13307721 is a deficient number, since it is larger than the sum of its proper divisors (7766199).

13307721 is a wasteful number, since it uses less digits than its factorization.

13307721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 293.

The product of its (nonzero) digits is 882, while the sum is 24.

The square root of 13307721 is about 3647.9749176769. The cubic root of 13307721 is about 236.9742890800.

It can be divided in two parts, 13307 and 721, that added together give a triangular number (14028 = T₁₆₇).

The spelling of 13307721 in words is "thirteen million, three hundred seven thousand, seven hundred twenty-one".