66305615620608 has 3600 divisors, whose sum is σ = 271364817649464. Its totient is φ = 15999141150720.

The previous prime is 66305615620603. The next prime is 66305615620609. The reversal of 66305615620608 is 80602651650366.

66305615620608 is a `hidden beast` number, since 6 + 6 + 3 + 0 + 5 + 6 + 1 + 5 + 6 + 20 + 608 = 666.

It can be written as a sum of positive squares in 12 ways, for example, as 6203925229824 + 60101690390784 = 2490768^2 + 7752528^2 .

It is a super-2 number, since 2×66305615620608² (a number of 28 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (66305615620603) by changing a digit.

It is a polite number, since it can be written in 359 ways as a sum of consecutive naturals, for example, 239370453366 + ... + 239370453642.

Almost surely, 2^{66305615620608} is an apocalyptic number.

66305615620608 is a gapful number since it is divisible by the number (68) 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 66305615620608, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (135682408824732).

66305615620608 is an abundant number, since it is smaller than the sum of its proper divisors (205059202028856).

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

66305615620608 is a wasteful number, since it uses less digits than its factorization.

66305615620608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 405 (or 360 counting only the distinct ones).

The product of its (nonzero) digits is 9331200, while the sum is 54.

The spelling of 66305615620608 in words is "sixty-six trillion, three hundred five billion, six hundred fifteen million, six hundred twenty thousand, six hundred eight".