16535453561 has 16 divisors (see below), whose sum is σ = 18257298048. Its totient is φ = 14974756720.

The previous prime is 16535453507. The next prime is 16535453591.

It is a happy number.

16535453561 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 16535453561 - 2⁶ = 16535453497 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16535453591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 326435 + ... + 373671.

It is an arithmetic number, because the mean of its divisors is an integer number (1141081128).

Almost surely, 2^16535453561 is an apocalyptic number.

16535453561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16535453561 is a deficient number, since it is larger than the sum of its proper divisors (1721844487).

16535453561 is an equidigital number, since it uses as much as digits as its factorization.

16535453561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47533 (or 47511 counting only the distinct ones).

The product of its digits is 810000, while the sum is 44.

Adding to 16535453561 its product of digits (810000), we get a palindrome (16536263561).

Subtracting from 16535453561 its product of digits (810000), we obtain a palindrome (16534643561).

The spelling of 16535453561 in words is "sixteen billion, five hundred thirty-five million, four hundred fifty-three thousand, five hundred sixty-one".