66404616777 has 16 divisors (see below), whose sum is σ = 98383817280. Its totient is φ = 44266771296.

The previous prime is 66404616769. The next prime is 66404616797. The reversal of 66404616777 is 77761640466.

66404616777 is a `hidden beast` number, since 6 + 6 + 404 + 6 + 167 + 77 = 666.

It is not a de Polignac number, because 66404616777 - 2³ = 66404616769 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66404616797) 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, 372453 + ... + 521085.

It is an arithmetic number, because the mean of its divisors is an integer number (6148988580).

Almost surely, 2^66404616777 is an apocalyptic number.

It is an amenable number.

66404616777 is a deficient number, since it is larger than the sum of its proper divisors (31979200503).

66404616777 is a wasteful number, since it uses less digits than its factorization.

66404616777 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 165189 (or 165183 counting only the distinct ones).

The product of its (nonzero) digits is 7112448, while the sum is 54.

The spelling of 66404616777 in words is "sixty-six billion, four hundred four million, six hundred sixteen thousand, seven hundred seventy-seven".