166749691 has 2 divisors, whose sum is σ = 166749692. Its totient is φ = 166749690.

The previous prime is 166749679. The next prime is 166749721. The reversal of 166749691 is 196947661.

It is a weak prime.

It is an emirp because it is prime and its reverse (196947661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166749691 is a prime.

It is not a weakly prime, because it can be changed into another prime (166749601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83374845 + 83374846.

It is an arithmetic number, because the mean of its divisors is an integer number (83374846).

Almost surely, 2^166749691 is an apocalyptic number.

166749691 is a deficient number, since it is larger than the sum of its proper divisors (1).

166749691 is an equidigital number, since it uses as much as digits as its factorization.

166749691 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 489888, while the sum is 49.

The square root of 166749691 is about 12913.1596056116. The cubic root of 166749691 is about 550.4125730826.

The spelling of 166749691 in words is "one hundred sixty-six million, seven hundred forty-nine thousand, six hundred ninety-one".