1666685351 has 2 divisors, whose sum is σ = 1666685352. Its totient is φ = 1666685350.

The previous prime is 1666685341. The next prime is 1666685399. The reversal of 1666685351 is 1535866661.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1666685351 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1666685296 and 1666685305.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1666685341) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833342675 + 833342676.

It is an arithmetic number, because the mean of its divisors is an integer number (833342676).

Almost surely, 2^1666685351 is an apocalyptic number.

1666685351 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666685351 is an equidigital number, since it uses as much as digits as its factorization.

1666685351 is an evil number, because the sum of its binary digits is even.

The product of its digits is 777600, while the sum is 47.

The square root of 1666685351 is about 40825.0578811592. The cubic root of 1666685351 is about 1185.6355320255.

The spelling of 1666685351 in words is "one billion, six hundred sixty-six million, six hundred eighty-five thousand, three hundred fifty-one".