668556477 has 48 divisors (see below), whose sum is σ = 1056314880. Its totient is φ = 417820032.

The previous prime is 668556463. The next prime is 668556503. The reversal of 668556477 is 774655866.

668556477 is a `hidden beast` number, since 6 + 6 + 8 + 5 + 564 + 77 = 666.

It is not a de Polignac number, because 668556477 - 2⁷ = 668556349 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (668556407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1101108 + ... + 1101714.

It is an arithmetic number, because the mean of its divisors is an integer number (22006560).

Almost surely, 2^668556477 is an apocalyptic number.

It is an amenable number.

668556477 is a deficient number, since it is larger than the sum of its proper divisors (387758403).

668556477 is a wasteful number, since it uses less digits than its factorization.

668556477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 767 (or 742 counting only the distinct ones).

The product of its digits is 8467200, while the sum is 54.

The square root of 668556477 is about 25856.4590963264. The cubic root of 668556477 is about 874.4051366843.

The spelling of 668556477 in words is "six hundred sixty-eight million, five hundred fifty-six thousand, four hundred seventy-seven".