13811021 has 12 divisors (see below), whose sum is σ = 16769568. Its totient is φ = 11140032.

The previous prime is 13810999. The next prime is 13811023. The reversal of 13811021 is 12011831.

It is not a de Polignac number, because 13811021 - 2¹⁴ = 13794637 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13811023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1391 + ... + 5436.

It is an arithmetic number, because the mean of its divisors is an integer number (1397464).

Almost surely, 2^13811021 is an apocalyptic number.

It is an amenable number.

13811021 is a deficient number, since it is larger than the sum of its proper divisors (2958547).

13811021 is an equidigital number, since it uses as much as digits as its factorization.

13811021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6868 (or 6851 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 17.

The square root of 13811021 is about 3716.3182048904. The cubic root of 13811021 is about 239.9248665278.

Adding to 13811021 its reverse (12011831), we get a palindrome (25822852).

The spelling of 13811021 in words is "thirteen million, eight hundred eleven thousand, twenty-one".