16663507909 has 16 divisors (see below), whose sum is σ = 17318070000. Its totient is φ = 16014458880.

The previous prime is 16663507897. The next prime is 16663507919. The reversal of 16663507909 is 90970536661.

It can be written as a sum of positive squares in 8 ways, for example, as 2107085409 + 14556422500 = 45903^2 + 120650^2 .

It is not a de Polignac number, because 16663507909 - 2²³ = 16655119301 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 (16663507919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7781979 + ... + 7784119.

It is an arithmetic number, because the mean of its divisors is an integer number (1082379375).

Almost surely, 2^16663507909 is an apocalyptic number.

It is an amenable number.

16663507909 is a deficient number, since it is larger than the sum of its proper divisors (654562091).

16663507909 is a wasteful number, since it uses less digits than its factorization.

16663507909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3288.

The product of its (nonzero) digits is 1837080, while the sum is 52.

The spelling of 16663507909 in words is "sixteen billion, six hundred sixty-three million, five hundred seven thousand, nine hundred nine".