166657781347 has 2 divisors, whose sum is σ = 166657781348. Its totient is φ = 166657781346.

The previous prime is 166657781309. The next prime is 166657781377. The reversal of 166657781347 is 743187756661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 166657781347 - 2¹⁹ = 166657257059 is a prime.

It is a super-2 number, since 2×166657781347² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (166657781377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83328890673 + 83328890674.

It is an arithmetic number, because the mean of its divisors is an integer number (83328890674).

Almost surely, 2^166657781347 is an apocalyptic number.

166657781347 is a deficient number, since it is larger than the sum of its proper divisors (1).

166657781347 is an equidigital number, since it uses as much as digits as its factorization.

166657781347 is an evil number, because the sum of its binary digits is even.

The product of its digits is 35562240, while the sum is 61.

The spelling of 166657781347 in words is "one hundred sixty-six billion, six hundred fifty-seven million, seven hundred eighty-one thousand, three hundred forty-seven".