13051721 has 2 divisors, whose sum is σ = 13051722. Its totient is φ = 13051720.

The previous prime is 13051697. The next prime is 13051723. The reversal of 13051721 is 12715031.

13051721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12996025 + 55696 = 3605^2 + 236^2 .

It is a cyclic number.

It is not a de Polignac number, because 13051721 - 2⁶ = 13051657 is a prime.

Together with 13051723, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 13051693 and 13051702.

It is not a weakly prime, because it can be changed into another prime (13051723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6525860 + 6525861.

It is an arithmetic number, because the mean of its divisors is an integer number (6525861).

Almost surely, 2^13051721 is an apocalyptic number.

It is an amenable number.

13051721 is a deficient number, since it is larger than the sum of its proper divisors (1).

13051721 is an equidigital number, since it uses as much as digits as its factorization.

13051721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 210, while the sum is 20.

The square root of 13051721 is about 3612.7165679029. The cubic root of 13051721 is about 235.4448853253. Note that the first 3 decimals are identical.

Adding to 13051721 its reverse (12715031), we get a palindrome (25766752).

The spelling of 13051721 in words is "thirteen million, fifty-one thousand, seven hundred twenty-one".