13661918 has 4 divisors (see below), whose sum is σ = 20492880. Its totient is φ = 6830958.

The previous prime is 13661909. The next prime is 13661927. The reversal of 13661918 is 81916631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81916631 = 37 ⋅2213963.

It is an interprime number because it is at equal distance from previous prime (13661909) and next prime (13661927).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3415478 + ... + 3415481.

It is an arithmetic number, because the mean of its divisors is an integer number (5123220).

Almost surely, 2^13661918 is an apocalyptic number.

13661918 is a deficient number, since it is larger than the sum of its proper divisors (6830962).

13661918 is an equidigital number, since it uses as much as digits as its factorization.

13661918 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6830961.

The product of its digits is 7776, while the sum is 35.

The square root of 13661918 is about 3696.2031870556. The cubic root of 13661918 is about 239.0583355790.

The spelling of 13661918 in words is "thirteen million, six hundred sixty-one thousand, nine hundred eighteen".