66815755986363 has 8 divisors (see below), whose sum is σ = 89090327227968. Its totient is φ = 44542511034504.

The previous prime is 66815755986347. The next prime is 66815755986587. The reversal of 66815755986363 is 36368955751866.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66815755986363 - 2⁴ = 66815755986347 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66815755986313) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 331454881 + ... + 331656402.

It is an arithmetic number, because the mean of its divisors is an integer number (11136290903496).

Almost surely, 2^{66815755986363} is an apocalyptic number.

66815755986363 is a deficient number, since it is larger than the sum of its proper divisors (22274571241605).

66815755986363 is a wasteful number, since it uses less digits than its factorization.

66815755986363 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 663144873.

The product of its digits is 5878656000, while the sum is 78.

The spelling of 66815755986363 in words is "sixty-six trillion, eight hundred fifteen billion, seven hundred fifty-five million, nine hundred eighty-six thousand, three hundred sixty-three".