13618381 has 4 divisors (see below), whose sum is σ = 15563872. Its totient is φ = 11672892.

The previous prime is 13618373. The next prime is 13618399. The reversal of 13618381 is 18381631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18381631 = 347 ⋅52973.

It is not a de Polignac number, because 13618381 - 2³ = 13618373 is a prime.

It is a super-2 number, since 2×13618381² = 370920602122322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13618301) 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, 972735 + ... + 972748.

It is an arithmetic number, because the mean of its divisors is an integer number (3890968).

Almost surely, 2^13618381 is an apocalyptic number.

It is an amenable number.

13618381 is a deficient number, since it is larger than the sum of its proper divisors (1945491).

13618381 is an equidigital number, since it uses as much as digits as its factorization.

13618381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1945490.

The product of its digits is 3456, while the sum is 31.

The square root of 13618381 is about 3690.3090656475. The cubic root of 13618381 is about 238.8041263209.

The spelling of 13618381 in words is "thirteen million, six hundred eighteen thousand, three hundred eighty-one".