16013855521 has 4 divisors (see below), whose sum is σ = 16068510612. Its totient is φ = 15959200432.

The previous prime is 16013855509. The next prime is 16013855587. The reversal of 16013855521 is 12555831061.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14288616225 + 1725239296 = 119535^2 + 41536^2 .

It is a cyclic number.

It is not a de Polignac number, because 16013855521 - 2⁷ = 16013855393 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16013855591) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27327106 + ... + 27327691.

It is an arithmetic number, because the mean of its divisors is an integer number (4017127653).

Almost surely, 2^16013855521 is an apocalyptic number.

It is an amenable number.

16013855521 is a deficient number, since it is larger than the sum of its proper divisors (54655091).

16013855521 is an equidigital number, since it uses as much as digits as its factorization.

16013855521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54655090.

The product of its (nonzero) digits is 36000, while the sum is 37.

The spelling of 16013855521 in words is "sixteen billion, thirteen million, eight hundred fifty-five thousand, five hundred twenty-one".