16644538969 has 4 divisors (see below), whose sum is σ = 16998678144. Its totient is φ = 16290399796.

The previous prime is 16644538949. The next prime is 16644538987. The reversal of 16644538969 is 96983544661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16644538969 - 2⁹ = 16644538457 is a prime.

It is a super-2 number, since 2×16644538969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16644538909) 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, 177069517 + ... + 177069610.

It is an arithmetic number, because the mean of its divisors is an integer number (4249669536).

Almost surely, 2^16644538969 is an apocalyptic number.

It is an amenable number.

16644538969 is a deficient number, since it is larger than the sum of its proper divisors (354139175).

16644538969 is an equidigital number, since it uses as much as digits as its factorization.

16644538969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354139174.

The product of its digits is 33592320, while the sum is 61.

The spelling of 16644538969 in words is "sixteen billion, six hundred forty-four million, five hundred thirty-eight thousand, nine hundred sixty-nine".