13860021 has 8 divisors (see below), whose sum is σ = 21120064. Its totient is φ = 7920000.

The previous prime is 13860017. The next prime is 13860037. The reversal of 13860021 is 12006831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 13860021 - 2² = 13860017 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21), and also a Moran number because the ratio is a prime number: 660001 = 13860021 / (1 + 3 + 8 + 6 + 0 + 0 + 2 + 1).

It is a self number, because there is not a number n which added to its sum of digits gives 13860021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13860001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 329980 + ... + 330021.

It is an arithmetic number, because the mean of its divisors is an integer number (2640008).

Almost surely, 2^13860021 is an apocalyptic number.

It is an amenable number.

13860021 is a deficient number, since it is larger than the sum of its proper divisors (7260043).

13860021 is an equidigital number, since it uses as much as digits as its factorization.

13860021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 660011.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 13860021 is about 3722.9049141766. The cubic root of 13860021 is about 240.2082740668.

Adding to 13860021 its reverse (12006831), we get a palindrome (25866852).

The spelling of 13860021 in words is "thirteen million, eight hundred sixty thousand, twenty-one".