667438680657 has 64 divisors (see below), whose sum is σ = 1050126704640. Its totient is φ = 369103682304.

The previous prime is 667438680641. The next prime is 667438680697. The reversal of 667438680657 is 756086834766.

It is not a de Polignac number, because 667438680657 - 2⁴ = 667438680641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (667438680697) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 225256258 + ... + 225259220.

It is an arithmetic number, because the mean of its divisors is an integer number (16408229760).

Almost surely, 2^667438680657 is an apocalyptic number.

It is an amenable number.

667438680657 is a deficient number, since it is larger than the sum of its proper divisors (382688023983).

667438680657 is a wasteful number, since it uses less digits than its factorization.

667438680657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4462.

The product of its (nonzero) digits is 243855360, while the sum is 66.

The spelling of 667438680657 in words is "six hundred sixty-seven billion, four hundred thirty-eight million, six hundred eighty thousand, six hundred fifty-seven".