13613881 has 4 divisors (see below), whose sum is σ = 13623012. Its totient is φ = 13604752.

The previous prime is 13613869. The next prime is 13613893. The reversal of 13613881 is 18831631.

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.

It is an interprime number because it is at equal distance from previous prime (13613869) and next prime (13613893).

It can be written as a sum of positive squares in 2 ways, for example, as 9241600 + 4372281 = 3040^2 + 2091^2 .

It is a cyclic number.

It is not a de Polignac number, because 13613881 - 2¹¹ = 13611833 is a prime.

It is a super-2 number, since 2×13613881² = 370675511764322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13613801) 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, 1750 + ... + 5503.

It is an arithmetic number, because the mean of its divisors is an integer number (3405753).

Almost surely, 2^13613881 is an apocalyptic number.

It is an amenable number.

13613881 is a deficient number, since it is larger than the sum of its proper divisors (9131).

13613881 is an equidigital number, since it uses as much as digits as its factorization.

13613881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9130.

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

The square root of 13613881 is about 3689.6993102420. The cubic root of 13613881 is about 238.7778202827. Note that the first 3 decimals are identical.

The spelling of 13613881 in words is "thirteen million, six hundred thirteen thousand, eight hundred eighty-one".