13708721 has 4 divisors (see below), whose sum is σ = 14763252. Its totient is φ = 12654192.

The previous prime is 13708703. The next prime is 13708729. The reversal of 13708721 is 12780731.

13708721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2686321 + 11022400 = 1639^2 + 3320^2 .

It is a cyclic number.

It is not a de Polignac number, because 13708721 - 2⁶ = 13708657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13708729) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 527246 + ... + 527271.

It is an arithmetic number, because the mean of its divisors is an integer number (3690813).

Almost surely, 2^13708721 is an apocalyptic number.

It is an amenable number.

13708721 is a deficient number, since it is larger than the sum of its proper divisors (1054531).

13708721 is a wasteful number, since it uses less digits than its factorization.

13708721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1054530.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 13708721 is about 3702.5290005616. The cubic root of 13708721 is about 239.3310131257.

The spelling of 13708721 in words is "thirteen million, seven hundred eight thousand, seven hundred twenty-one".