16521045161 has 4 divisors (see below), whose sum is σ = 16923997524. Its totient is φ = 16118092800.

The previous prime is 16521045157. The next prime is 16521045181. The reversal of 16521045161 is 16154012561.

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 3286843561 + 13234201600 = 57331^2 + 115040^2 .

It is a cyclic number.

It is not a de Polignac number, because 16521045161 - 2² = 16521045157 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16521045181) 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, 201476120 + ... + 201476201.

It is an arithmetic number, because the mean of its divisors is an integer number (4230999381).

Almost surely, 2^16521045161 is an apocalyptic number.

It is an amenable number.

16521045161 is a deficient number, since it is larger than the sum of its proper divisors (402952363).

16521045161 is an equidigital number, since it uses as much as digits as its factorization.

16521045161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 402952362.

The product of its (nonzero) digits is 7200, while the sum is 32.

The spelling of 16521045161 in words is "sixteen billion, five hundred twenty-one million, forty-five thousand, one hundred sixty-one".