189668749 has 4 divisors (see below), whose sum is σ = 189697564. Its totient is φ = 189639936.

The previous prime is 189668719. The next prime is 189668777. The reversal of 189668749 is 947866981.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 43428100 + 146240649 = 6590^2 + 12093^2 .

It is a cyclic number.

It is not a de Polignac number, because 189668749 - 2¹⁵ = 189635981 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 189668693 and 189668702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (189668719) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 859 + ... + 19495.

It is an arithmetic number, because the mean of its divisors is an integer number (47424391).

Almost surely, 2^189668749 is an apocalyptic number.

It is an amenable number.

189668749 is a deficient number, since it is larger than the sum of its proper divisors (28815).

189668749 is a wasteful number, since it uses less digits than its factorization.

189668749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28814.

The product of its digits is 5225472, while the sum is 58.

The square root of 189668749 is about 13772.0277737158. The cubic root of 189668749 is about 574.5554209358. Note that the first 3 decimals are identical.

The spelling of 189668749 in words is "one hundred eighty-nine million, six hundred sixty-eight thousand, seven hundred forty-nine".