66355478677 has 16 divisors (see below), whose sum is σ = 67237449840. Its totient is φ = 65480583168.

The previous prime is 66355478663. The next prime is 66355478711. The reversal of 66355478677 is 77687455366.

It can be written as a sum of positive squares in 8 ways, for example, as 30624650001 + 35730828676 = 174999^2 + 189026^2 .

It is a cyclic number.

It is not a de Polignac number, because 66355478677 - 2⁷ = 66355478549 is a prime.

It is a Duffinian number.

Its product of digits (177811200) is a multiple of the sum of its prime divisors (4200).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66355478977) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20937349 + ... + 20940517.

It is an arithmetic number, because the mean of its divisors is an integer number (4202340615).

Almost surely, 2^66355478677 is an apocalyptic number.

It is an amenable number.

66355478677 is a deficient number, since it is larger than the sum of its proper divisors (881971163).

66355478677 is a wasteful number, since it uses less digits than its factorization.

66355478677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4200.

The product of its digits is 177811200, while the sum is 64.

The spelling of 66355478677 in words is "sixty-six billion, three hundred fifty-five million, four hundred seventy-eight thousand, six hundred seventy-seven".