13121918 has 4 divisors (see below), whose sum is σ = 19682880. Its totient is φ = 6560958.

The previous prime is 13121887. The next prime is 13121921. The reversal of 13121918 is 81912131.

It is a semiprime because it is the product of two primes.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3280478 + ... + 3280481.

It is an arithmetic number, because the mean of its divisors is an integer number (4920720).

Almost surely, 2^13121918 is an apocalyptic number.

13121918 is a deficient number, since it is larger than the sum of its proper divisors (6560962).

13121918 is an equidigital number, since it uses as much as digits as its factorization.

13121918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6560961.

The product of its digits is 432, while the sum is 26.

The square root of 13121918 is about 3622.4188051632. The cubic root of 13121918 is about 235.8662341637.

The spelling of 13121918 in words is "thirteen million, one hundred twenty-one thousand, nine hundred eighteen".