66501612262800 has 2400 divisors, whose sum is σ = 291609082490880. Its totient is φ = 14293532160000.

The previous prime is 66501612262649. The next prime is 66501612262837. The reversal of 66501612262800 is 826221610566.

66501612262800 is a `hidden beast` number, since 6 + 6 + 5 + 0 + 1 + 6 + 12 + 2 + 628 + 0 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 479 ways as a sum of consecutive naturals, for example, 19964457135 + ... + 19964460465.

Almost surely, 2^{66501612262800} is an apocalyptic number.

66501612262800 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 66501612262800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (145804541245440).

66501612262800 is an abundant number, since it is smaller than the sum of its proper divisors (225107470228080).

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

66501612262800 is a wasteful number, since it uses less digits than its factorization.

66501612262800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3555 (or 3535 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The spelling of 66501612262800 in words is "sixty-six trillion, five hundred one billion, six hundred twelve million, two hundred sixty-two thousand, eight hundred".