66256619293440 has 720 divisors, whose sum is σ = 239597598240000. Its totient is φ = 17480996757504.

The previous prime is 66256619293439. The next prime is 66256619293453. The reversal of 66256619293440 is 4439291665266.

66256619293440 is a `hidden beast` number, since 6 + 6 + 2 + 5 + 6 + 619 + 2 + 9 + 3 + 4 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 16007878891 + ... + 16007883029.

It is an arithmetic number, because the mean of its divisors is an integer number (332774442000).

Almost surely, 2^{66256619293440} is an apocalyptic number.

66256619293440 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 66256619293440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119798799120000).

66256619293440 is an abundant number, since it is smaller than the sum of its proper divisors (173340978946560).

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

66256619293440 is a wasteful number, since it uses less digits than its factorization.

66256619293440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5774 (or 5751 counting only the distinct ones).

The product of its (nonzero) digits is 100776960, while the sum is 63.

The spelling of 66256619293440 in words is "sixty-six trillion, two hundred fifty-six billion, six hundred nineteen million, two hundred ninety-three thousand, four hundred forty".