16542406521 has 12 divisors (see below), whose sum is σ = 24779572272. Its totient is φ = 11028270852.

The previous prime is 16542406513. The next prime is 16542406561. The reversal of 16542406521 is 12560424561.

16542406521 is a `hidden beast` number, since 16 + 542 + 40 + 65 + 2 + 1 = 666.

16542406521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16542406521 - 2³ = 16542406513 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16542406501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 34037631 + ... + 34038116.

It is an arithmetic number, because the mean of its divisors is an integer number (2064964356).

Almost surely, 2^16542406521 is an apocalyptic number.

It is an amenable number.

16542406521 is a deficient number, since it is larger than the sum of its proper divisors (8237165751).

16542406521 is an frugal number, since it uses more digits than its factorization.

16542406521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 68075762 (or 68075750 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The spelling of 16542406521 in words is "sixteen billion, five hundred forty-two million, four hundred six thousand, five hundred twenty-one".