16668636544 has 256 divisors, whose sum is σ = 42830208000. Its totient is φ = 6424535040.

The previous prime is 16668636541. The next prime is 16668636553. The reversal of 16668636544 is 44563686661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16668636541) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17165979 + ... + 17166949.

It is an arithmetic number, because the mean of its divisors is an integer number (167305500).

Almost surely, 2^16668636544 is an apocalyptic number.

16668636544 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16668636544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21415104000).

16668636544 is an abundant number, since it is smaller than the sum of its proper divisors (26161571456).

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

16668636544 is an equidigital number, since it uses as much as digits as its factorization.

16668636544 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1046 (or 1020 counting only the distinct ones).

The product of its digits is 14929920, while the sum is 55.

It can be divided in two parts, 1666 and 8636544, that multiplied together give a square (14388482304 = 119952²).

The spelling of 16668636544 in words is "sixteen billion, six hundred sixty-eight million, six hundred thirty-six thousand, five hundred forty-four".