16444121561 has 16 divisors (see below), whose sum is σ = 19638893568. Its totient is φ = 13462534800.

The previous prime is 16444121549. The next prime is 16444121563. The reversal of 16444121561 is 16512144461.

16444121561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 16444121561 - 2⁶ = 16444121497 is a prime.

It is a super-3 number, since 3×16444121561³ (a number of 32 digits) contains 333 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (16444121563) 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 15 ways as a sum of consecutive naturals, for example, 37346 + ... + 185156.

It is an arithmetic number, because the mean of its divisors is an integer number (1227430848).

Almost surely, 2^16444121561 is an apocalyptic number.

It is an amenable number.

16444121561 is a deficient number, since it is larger than the sum of its proper divisors (3194772007).

16444121561 is a wasteful number, since it uses less digits than its factorization.

16444121561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148532.

The product of its digits is 23040, while the sum is 35.

The spelling of 16444121561 in words is "sixteen billion, four hundred forty-four million, one hundred twenty-one thousand, five hundred sixty-one".