66704994720 has 384 divisors, whose sum is σ = 287346286080. Its totient is φ = 14073937920.

The previous prime is 66704994647. The next prime is 66704994739. The reversal of 66704994720 is 2749940766.

It is a happy number.

66704994720 is a `hidden beast` number, since 66 + 70 + 49 + 9 + 472 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 308280 + ... + 477960.

It is an arithmetic number, because the mean of its divisors is an integer number (748297620).

Almost surely, 2^66704994720 is an apocalyptic number.

66704994720 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 66704994720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143673143040).

66704994720 is an abundant number, since it is smaller than the sum of its proper divisors (220641291360).

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

66704994720 is a wasteful number, since it uses less digits than its factorization.

66704994720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 169725 (or 169711 counting only the distinct ones).

The product of its (nonzero) digits is 4572288, while the sum is 54.

The spelling of 66704994720 in words is "sixty-six billion, seven hundred four million, nine hundred ninety-four thousand, seven hundred twenty".