66488377978 has 8 divisors (see below), whose sum is σ = 108799164000. Its totient is φ = 30221989980.

The previous prime is 66488377957. The next prime is 66488377979. The reversal of 66488377978 is 87977388466.

66488377978 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a super-2 number, since 2×66488377978² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66488377978.

It is not an unprimeable number, because it can be changed into a prime (66488377979) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1511099478 + ... + 1511099521.

It is an arithmetic number, because the mean of its divisors is an integer number (13599895500).

Almost surely, 2^66488377978 is an apocalyptic number.

66488377978 is a deficient number, since it is larger than the sum of its proper divisors (42310786022).

66488377978 is a wasteful number, since it uses less digits than its factorization.

66488377978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3022199012.

The product of its digits is 682795008, while the sum is 73.

The spelling of 66488377978 in words is "sixty-six billion, four hundred eighty-eight million, three hundred seventy-seven thousand, nine hundred seventy-eight".