13866381 has 6 divisors (see below), whose sum is σ = 20029230. Its totient is φ = 9244248.

The previous prime is 13866367. The next prime is 13866389. The reversal of 13866381 is 18366831.

13866381 is a `hidden beast` number, since 13 + 8 + 6 + 638 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 12744900 + 1121481 = 3570^2 + 1059^2 .

It is not a de Polignac number, because 13866381 - 2¹³ = 13858189 is a prime.

It is a super-2 number, since 2×13866381² = 384553044074322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13866389) by changing a digit.

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 in 5 ways as a sum of consecutive naturals, for example, 770346 + ... + 770363.

It is an arithmetic number, because the mean of its divisors is an integer number (3338205).

Almost surely, 2^13866381 is an apocalyptic number.

It is an amenable number.

13866381 is a deficient number, since it is larger than the sum of its proper divisors (6162849).

13866381 is a wasteful number, since it uses less digits than its factorization.

13866381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1540715 (or 1540712 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 13866381 is about 3723.7589879046. The cubic root of 13866381 is about 240.2450102065.

The spelling of 13866381 in words is "thirteen million, eight hundred sixty-six thousand, three hundred eighty-one".