16561442132 has 36 divisors (see below), whose sum is σ = 29492395380. Its totient is φ = 8137389312.

The previous prime is 16561442099. The next prime is 16561442137. The reversal of 16561442132 is 23124416561.

It can be written as a sum of positive squares in 2 ways, for example, as 8927226256 + 7634215876 = 94484^2 + 87374^2 .

It is a junction number, because it is equal to n+sod(n) for n = 16561442092 and 16561442101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561442137) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5715308 + ... + 5718204.

It is an arithmetic number, because the mean of its divisors is an integer number (819233205).

Almost surely, 2^16561442132 is an apocalyptic number.

It is an amenable number.

16561442132 is a deficient number, since it is larger than the sum of its proper divisors (12930953248).

16561442132 is a wasteful number, since it uses less digits than its factorization.

16561442132 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3288 (or 3207 counting only the distinct ones).

The product of its digits is 34560, while the sum is 35.

Adding to 16561442132 its reverse (23124416561), we get a palindrome (39685858693).

The spelling of 16561442132 in words is "sixteen billion, five hundred sixty-one million, four hundred forty-two thousand, one hundred thirty-two".