66490744320 has 1920 divisors, whose sum is σ = 327669027840. Its totient is φ = 12342067200.

The previous prime is 66490744277. The next prime is 66490744357. The reversal of 66490744320 is 2344709466.

It is a happy number.

66490744320 is a `hidden beast` number, since 6 + 64 + 90 + 74 + 432 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1920).

It is a super-2 number, since 2×66490744320² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

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 191 ways as a sum of consecutive naturals, for example, 2144862705 + ... + 2144862735.

It is an arithmetic number, because the mean of its divisors is an integer number (170660952).

Almost surely, 2^66490744320 is an apocalyptic number.

66490744320 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 66490744320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (163834513920).

66490744320 is an abundant number, since it is smaller than the sum of its proper divisors (261178283520).

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

66490744320 is a wasteful number, since it uses less digits than its factorization.

66490744320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 72 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 45.

The spelling of 66490744320 in words is "sixty-six billion, four hundred ninety million, seven hundred forty-four thousand, three hundred twenty".