13726657661 has 2 divisors, whose sum is σ = 13726657662. Its totient is φ = 13726657660.

The previous prime is 13726657627. The next prime is 13726657723. The reversal of 13726657661 is 16675662731.

13726657661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7672884025 + 6053773636 = 87595^2 + 77806^2 .

It is a cyclic number.

It is not a de Polignac number, because 13726657661 - 2¹⁰ = 13726656637 is a prime.

It is a super-2 number, since 2×13726657661² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13726651661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6863328830 + 6863328831.

It is an arithmetic number, because the mean of its divisors is an integer number (6863328831).

Almost surely, 2^13726657661 is an apocalyptic number.

It is an amenable number.

13726657661 is a deficient number, since it is larger than the sum of its proper divisors (1).

13726657661 is an equidigital number, since it uses as much as digits as its factorization.

13726657661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1905120, while the sum is 50.

The spelling of 13726657661 in words is "thirteen billion, seven hundred twenty-six million, six hundred fifty-seven thousand, six hundred sixty-one".