13820521 has 16 divisors (see below), whose sum is σ = 16386048. Its totient is φ = 11491200.

The previous prime is 13820509. The next prime is 13820531. The reversal of 13820521 is 12502831.

13820521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 13820521 - 2⁵ = 13820489 is a prime.

It is a super-2 number, since 2×13820521² = 382013601422882, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 13820492 and 13820501.

It is not an unprimeable number, because it can be changed into a prime (13820531) 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, 17781 + ... + 18541.

It is an arithmetic number, because the mean of its divisors is an integer number (1024128).

Almost surely, 2^13820521 is an apocalyptic number.

13820521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

13820521 is a deficient number, since it is larger than the sum of its proper divisors (2565527).

13820521 is a wasteful number, since it uses less digits than its factorization.

13820521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 912.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 13820521 is about 3717.5961319110. The cubic root of 13820521 is about 239.9798652090.

It can be divided in two parts, 13820 and 521, that added together give a palindrome (14341).

The spelling of 13820521 in words is "thirteen million, eight hundred twenty thousand, five hundred twenty-one".