13756661 has 4 divisors (see below), whose sum is σ = 13764300. Its totient is φ = 13749024.

The previous prime is 13756657. The next prime is 13756667. The reversal of 13756661 is 16665731.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16665731 = 23 ⋅724597.

It can be written as a sum of positive squares in 2 ways, for example, as 5317636 + 8439025 = 2306^2 + 2905^2 .

It is a cyclic number.

It is not a de Polignac number, because 13756661 - 2² = 13756657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13756667) 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, 545 + ... + 5273.

It is an arithmetic number, because the mean of its divisors is an integer number (3441075).

Almost surely, 2^13756661 is an apocalyptic number.

It is an amenable number.

13756661 is a deficient number, since it is larger than the sum of its proper divisors (7639).

13756661 is an equidigital number, since it uses as much as digits as its factorization.

13756661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7638.

The product of its digits is 22680, while the sum is 35.

The square root of 13756661 is about 3708.9973038545. The cubic root of 13756661 is about 239.6096722414.

The spelling of 13756661 in words is "thirteen million, seven hundred fifty-six thousand, six hundred sixty-one".