66811530240 has 1408 divisors, whose sum is σ = 301087825920. Its totient is φ = 13674479616.

The previous prime is 66811530209. The next prime is 66811530241. The reversal of 66811530240 is 4203511866.

It is a happy number.

66811530240 is a `hidden beast` number, since 6 + 6 + 81 + 1 + 530 + 2 + 40 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 66811530195 and 66811530204.

It is not an unprimeable number, because it can be changed into a prime (66811530241) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 591252424 + ... + 591252536.

Almost surely, 2^66811530240 is an apocalyptic number.

66811530240 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 66811530240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (150543912960).

66811530240 is an abundant number, since it is smaller than the sum of its proper divisors (234276295680).

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

66811530240 is a wasteful number, since it uses less digits than its factorization.

66811530240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 190 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The spelling of 66811530240 in words is "sixty-six billion, eight hundred eleven million, five hundred thirty thousand, two hundred forty".