16326861661 has 6 divisors (see below), whose sum is σ = 17946054686. Its totient is φ = 14842601400.

The previous prime is 16326861653. The next prime is 16326861767. The reversal of 16326861661 is 16616862361.

16326861661 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 15921644761 + 405216900 = 126181^2 + 20130^2 .

It is not a de Polignac number, because 16326861661 - 2³ = 16326861653 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 (16326861361) 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 5 ways as a sum of consecutive naturals, for example, 67466250 + ... + 67466491.

Almost surely, 2^16326861661 is an apocalyptic number.

16326861661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

16326861661 is a deficient number, since it is larger than the sum of its proper divisors (1619193025).

16326861661 is a wasteful number, since it uses less digits than its factorization.

16326861661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134932763 (or 134932752 counting only the distinct ones).

The product of its digits is 373248, while the sum is 46.

The spelling of 16326861661 in words is "sixteen billion, three hundred twenty-six million, eight hundred sixty-one thousand, six hundred sixty-one".