13888821 has 4 divisors (see below), whose sum is σ = 18518432. Its totient is φ = 9259212.

The previous prime is 13888817. The next prime is 13888841. The reversal of 13888821 is 12888831.

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: 12888831 = 3 ⋅4296277.

It is not a de Polignac number, because 13888821 - 2² = 13888817 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 13888821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13888841) 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, 2314801 + ... + 2314806.

It is an arithmetic number, because the mean of its divisors is an integer number (4629608).

Almost surely, 2^13888821 is an apocalyptic number.

It is an amenable number.

13888821 is a deficient number, since it is larger than the sum of its proper divisors (4629611).

13888821 is an equidigital number, since it uses as much as digits as its factorization.

13888821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4629610.

The product of its digits is 24576, while the sum is 39.

The square root of 13888821 is about 3726.7708542383. The cubic root of 13888821 is about 240.3745367330.

The spelling of 13888821 in words is "thirteen million, eight hundred eighty-eight thousand, eight hundred twenty-one".