16521143918389 has 4 divisors (see below), whose sum is σ = 18023066092800. Its totient is φ = 15019221743980.

The previous prime is 16521143918339. The next prime is 16521143918393. The reversal of 16521143918389 is 98381934112561.

16521143918389 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16521143918389 - 2⁹ = 16521143917877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16521143918339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 750961087189 + ... + 750961087210.

It is an arithmetic number, because the mean of its divisors is an integer number (4505766523200).

Almost surely, 2^{16521143918389} is an apocalyptic number.

It is an amenable number.

16521143918389 is a deficient number, since it is larger than the sum of its proper divisors (1501922174411).

16521143918389 is a wasteful number, since it uses less digits than its factorization.

16521143918389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1501922174410.

The product of its digits is 11197440, while the sum is 61.

The spelling of 16521143918389 in words is "sixteen trillion, five hundred twenty-one billion, one hundred forty-three million, nine hundred eighteen thousand, three hundred eighty-nine".