13820115521 has 4 divisors (see below), whose sum is σ = 13850356932. Its totient is φ = 13789874112.

The previous prime is 13820115499. The next prime is 13820115577. The reversal of 13820115521 is 12551102831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12551102831 = 67 ⋅187329893.

It can be written as a sum of positive squares in 2 ways, for example, as 10740420496 + 3079695025 = 103636^2 + 55495^2 .

It is a cyclic number.

It is not a de Polignac number, because 13820115521 - 2⁶ = 13820115457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (13820115581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15120020 + ... + 15120933.

It is an arithmetic number, because the mean of its divisors is an integer number (3462589233).

Almost surely, 2^13820115521 is an apocalyptic number.

It is an amenable number.

13820115521 is a deficient number, since it is larger than the sum of its proper divisors (30241411).

13820115521 is an equidigital number, since it uses as much as digits as its factorization.

13820115521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30241410.

The product of its (nonzero) digits is 2400, while the sum is 29.

The spelling of 13820115521 in words is "thirteen billion, eight hundred twenty million, one hundred fifteen thousand, five hundred twenty-one".