13545661 has 4 divisors (see below), whose sum is σ = 13731292. Its totient is φ = 13360032.

The previous prime is 13545647. The next prime is 13545691. The reversal of 13545661 is 16654531.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16654531 = 83 ⋅200657.

It can be written as a sum of positive squares in 2 ways, for example, as 8732025 + 4813636 = 2955^2 + 2194^2 .

It is a cyclic number.

It is not a de Polignac number, because 13545661 - 2⁵ = 13545629 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13545691) 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, 92706 + ... + 92851.

It is an arithmetic number, because the mean of its divisors is an integer number (3432823).

Almost surely, 2^13545661 is an apocalyptic number.

It is an amenable number.

13545661 is a deficient number, since it is larger than the sum of its proper divisors (185631).

13545661 is an equidigital number, since it uses as much as digits as its factorization.

13545661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 185630.

The product of its digits is 10800, while the sum is 31.

The square root of 13545661 is about 3680.4430439826. The cubic root of 13545661 is about 238.3783087350.

It can be divided in two parts, 135 and 45661, that added together give a square (45796 = 214²).

The spelling of 13545661 in words is "thirteen million, five hundred forty-five thousand, six hundred sixty-one".