1666839623459 has 2 divisors, whose sum is σ = 1666839623460. Its totient is φ = 1666839623458.

The previous prime is 1666839623447. The next prime is 1666839623479. The reversal of 1666839623459 is 9543269386661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1666839623459 - 2¹² = 1666839619363 is a prime.

It is not a weakly prime, because it can be changed into another prime (1666839623479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833419811729 + 833419811730.

It is an arithmetic number, because the mean of its divisors is an integer number (833419811730).

Almost surely, 2^{1666839623459} is an apocalyptic number.

1666839623459 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666839623459 is an equidigital number, since it uses as much as digits as its factorization.

1666839623459 is an evil number, because the sum of its binary digits is even.

The product of its digits is 302330880, while the sum is 68.

The spelling of 1666839623459 in words is "one trillion, six hundred sixty-six billion, eight hundred thirty-nine million, six hundred twenty-three thousand, four hundred fifty-nine".