66756519786020 has 96 divisors (see below), whose sum is σ = 150894959292000. Its totient is φ = 24715524464640.

The previous prime is 66756519786001. The next prime is 66756519786043. The reversal of 66756519786020 is 2068791565766.

It can be written as a sum of positive squares in 16 ways, for example, as 52732228796416 + 14024290989604 = 7261696^2 + 3744902^2 .

It is a Harshad number since it is a multiple of its sum of digits (68).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118954322 + ... + 119514198.

It is an arithmetic number, because the mean of its divisors is an integer number (1571822492625).

Almost surely, 2^{66756519786020} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66756519786020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (75447479646000).

66756519786020 is an abundant number, since it is smaller than the sum of its proper divisors (84138439505980).

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

66756519786020 is a wasteful number, since it uses less digits than its factorization.

66756519786020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565713 (or 565711 counting only the distinct ones).

The product of its (nonzero) digits is 228614400, while the sum is 68.

The spelling of 66756519786020 in words is "sixty-six trillion, seven hundred fifty-six billion, five hundred nineteen million, seven hundred eighty-six thousand, twenty".