667857535045381 has 2 divisors, whose sum is σ = 667857535045382. Its totient is φ = 667857535045380.

The previous prime is 667857535045279. The next prime is 667857535045537. The reversal of 667857535045381 is 183540535758766.

667857535045381 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 618792987802500 + 49064547242881 = 24875550^2 + 7004609^2 .

It is a cyclic number.

It is not a de Polignac number, because 667857535045381 - 2³⁹ = 667307779231493 is a prime.

It is a super-2 number, since 2×667857535045381² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (667857535045781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333928767522690 + 333928767522691.

It is an arithmetic number, because the mean of its divisors is an integer number (333928767522691).

Almost surely, 2^{667857535045381} is an apocalyptic number.

It is an amenable number.

667857535045381 is a deficient number, since it is larger than the sum of its proper divisors (1).

667857535045381 is an equidigital number, since it uses as much as digits as its factorization.

667857535045381 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2540160000, while the sum is 73.

The spelling of 667857535045381 in words is "six hundred sixty-seven trillion, eight hundred fifty-seven billion, five hundred thirty-five million, forty-five thousand, three hundred eighty-one".