17991609216 has 64 divisors (see below), whose sum is σ = 54617393280. Its totient is φ = 5140459008.

The previous prime is 17991609203. The next prime is 17991609239. The reversal of 17991609216 is 61290619971.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×17991609216² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3343966 + ... + 3349341.

It is an arithmetic number, because the mean of its divisors is an integer number (853396770).

Almost surely, 2^17991609216 is an apocalyptic number.

17991609216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

17991609216 is an abundant number, since it is smaller than the sum of its proper divisors (36625784064).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

17991609216 is an equidigital number, since it uses as much as digits as its factorization.

17991609216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6693331 (or 6693319 counting only the distinct ones).

The product of its (nonzero) digits is 367416, while the sum is 51.

The spelling of 17991609216 in words is "seventeen billion, nine hundred ninety-one million, six hundred nine thousand, two hundred sixteen".