191738889 has 6 divisors (see below), whose sum is σ = 276956186. Its totient is φ = 127825920.

The previous prime is 191738887. The next prime is 191738947. The reversal of 191738889 is 988837191.

191738889 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 132710400 + 59028489 = 11520^2 + 7683^2 .

It is not a de Polignac number, because 191738889 - 2¹ = 191738887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191738887) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10652152 + ... + 10652169.

Almost surely, 2^191738889 is an apocalyptic number.

It is an amenable number.

191738889 is a deficient number, since it is larger than the sum of its proper divisors (85217297).

191738889 is a wasteful number, since it uses less digits than its factorization.

191738889 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21304327 (or 21304324 counting only the distinct ones).

The product of its digits is 870912, while the sum is 54.

The square root of 191738889 is about 13846.9812233570. The cubic root of 191738889 is about 576.6381905741.

The spelling of 191738889 in words is "one hundred ninety-one million, seven hundred thirty-eight thousand, eight hundred eighty-nine".