666668783877 has 32 divisors (see below), whose sum is σ = 953337911040. Its totient is φ = 413454328320.

The previous prime is 666668783861. The next prime is 666668783887. The reversal of 666668783877 is 778387866666.

It is not a de Polignac number, because 666668783877 - 2⁴ = 666668783861 is a prime.

It is a super-2 number, since 2×666668783877² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666668783887) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 515238 + ... + 1264439.

It is an arithmetic number, because the mean of its divisors is an integer number (29791809720).

Almost surely, 2^666668783877 is an apocalyptic number.

It is an amenable number.

666668783877 is a deficient number, since it is larger than the sum of its proper divisors (286669127163).

666668783877 is a wasteful number, since it uses less digits than its factorization.

666668783877 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1779853.

The product of its digits is 4096770048, while the sum is 78.

The spelling of 666668783877 in words is "six hundred sixty-six billion, six hundred sixty-eight million, seven hundred eighty-three thousand, eight hundred seventy-seven".