13821387 has 16 divisors (see below), whose sum is σ = 19394592. Its totient is φ = 8743680.

The previous prime is 13821383. The next prime is 13821407. The reversal of 13821387 is 78312831.

It is not a de Polignac number, because 13821387 - 2² = 13821383 is a prime.

It is not an unprimeable number, because it can be changed into a prime (13821383) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3033 + ... + 6069.

It is an arithmetic number, because the mean of its divisors is an integer number (1212162).

Almost surely, 2^13821387 is an apocalyptic number.

13821387 is a deficient number, since it is larger than the sum of its proper divisors (5573205).

13821387 is a wasteful number, since it uses less digits than its factorization.

13821387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3118.

The product of its digits is 8064, while the sum is 33.

The square root of 13821387 is about 3717.7126032011. The cubic root of 13821387 is about 239.9848775194.

The spelling of 13821387 in words is "thirteen million, eight hundred twenty-one thousand, three hundred eighty-seven".