16666493 has 2 divisors, whose sum is σ = 16666494. Its totient is φ = 16666492.

The previous prime is 16666487. The next prime is 16666501. The reversal of 16666493 is 39466661.

16666493 is nontrivially palindromic in base 12.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14273284 + 2393209 = 3778^2 + 1547^2 .

It is a cyclic number.

It is not a de Polignac number, because 16666493 - 2¹⁰ = 16665469 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 16666493.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16666423) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8333246 + 8333247.

It is an arithmetic number, because the mean of its divisors is an integer number (8333247).

Almost surely, 2^16666493 is an apocalyptic number.

It is an amenable number.

16666493 is a deficient number, since it is larger than the sum of its proper divisors (1).

16666493 is an equidigital number, since it uses as much as digits as its factorization.

16666493 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 41.

The square root of 16666493 is about 4082.4616348473. The cubic root of 16666493 is about 255.4355902454.

The spelling of 16666493 in words is "sixteen million, six hundred sixty-six thousand, four hundred ninety-three".