66688199424 has 540 divisors, whose sum is σ = 249863522832. Its totient is φ = 17317048320.

The previous prime is 66688199419. The next prime is 66688199429. The reversal of 66688199424 is 42499188666.

It is an interprime number because it is at equal distance from previous prime (66688199419) and next prime (66688199429).

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (66688199429) 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 59 ways as a sum of consecutive naturals, for example, 17561494 + ... + 17565290.

Almost surely, 2^66688199424 is an apocalyptic number.

66688199424 is a gapful number since it is divisible by the number (64) 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 66688199424, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124931761416).

66688199424 is an abundant number, since it is smaller than the sum of its proper divisors (183175323408).

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

66688199424 is a wasteful number, since it uses less digits than its factorization.

66688199424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3854 (or 3820 counting only the distinct ones).

The product of its digits is 35831808, while the sum is 63.

The spelling of 66688199424 in words is "sixty-six billion, six hundred eighty-eight million, one hundred ninety-nine thousand, four hundred twenty-four".