66799434240 has 1440 divisors, whose sum is σ = 305251087680. Its totient is φ = 13795246080.

The previous prime is 66799434223. The next prime is 66799434257. The reversal of 66799434240 is 4243499766.

66799434240 is a `hidden beast` number, since 66 + 79 + 94 + 3 + 424 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (66799434223) and next prime (66799434257).

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

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 143 ways as a sum of consecutive naturals, for example, 409812399 + ... + 409812561.

It is an arithmetic number, because the mean of its divisors is an integer number (211979922).

Almost surely, 2^66799434240 is an apocalyptic number.

66799434240 is a gapful number since it is divisible by the number (60) 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 66799434240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (152625543840).

66799434240 is an abundant number, since it is smaller than the sum of its proper divisors (238451653440).

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

66799434240 is a wasteful number, since it uses less digits than its factorization.

66799434240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 231 (or 191 counting only the distinct ones).

The product of its (nonzero) digits is 7838208, while the sum is 54.

The spelling of 66799434240 in words is "sixty-six billion, seven hundred ninety-nine million, four hundred thirty-four thousand, two hundred forty".