13126721 has 8 divisors (see below), whose sum is σ = 13780800. Its totient is φ = 12479632.

The previous prime is 13126717. The next prime is 13126723. The reversal of 13126721 is 12762131.

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

It is a cyclic number.

It is not a de Polignac number, because 13126721 - 2² = 13126717 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (13126723) 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, 2330 + ... + 5628.

It is an arithmetic number, because the mean of its divisors is an integer number (1722600).

Almost surely, 2^13126721 is an apocalyptic number.

It is an amenable number.

13126721 is a deficient number, since it is larger than the sum of its proper divisors (654079).

13126721 is a wasteful number, since it uses less digits than its factorization.

13126721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3495.

The product of its digits is 504, while the sum is 23.

The square root of 13126721 is about 3623.0816993272. The cubic root of 13126721 is about 235.8950085987.

Adding to 13126721 its reverse (12762131), we get a palindrome (25888852).

The spelling of 13126721 in words is "thirteen million, one hundred twenty-six thousand, seven hundred twenty-one".