66722746587840 has 672 divisors, whose sum is σ = 277152141127680. Its totient is φ = 14403166322688.

The previous prime is 66722746587821. The next prime is 66722746587853. The reversal of 66722746587840 is 4878564722766.

66722746587840 is a `hidden beast` number, since 6 + 6 + 7 + 2 + 2 + 7 + 465 + 87 + 84 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a super-2 number, since 2×66722746587840² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (72).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 35719972 + ... + 37541468.

It is an arithmetic number, because the mean of its divisors is an integer number (412428781440).

Almost surely, 2^{66722746587840} is an apocalyptic number.

66722746587840 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 66722746587840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (138576070563840).

66722746587840 is an abundant number, since it is smaller than the sum of its proper divisors (210429394539840).

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

66722746587840 is a wasteful number, since it uses less digits than its factorization.

66722746587840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1821629 (or 1821616 counting only the distinct ones).

The product of its (nonzero) digits is 1517322240, while the sum is 72.

The spelling of 66722746587840 in words is "sixty-six trillion, seven hundred twenty-two billion, seven hundred forty-six million, five hundred eighty-seven thousand, eight hundred forty".