191154989 has 6 divisors (see below), whose sum is σ = 191920170. Its totient is φ = 190391600.

The previous prime is 191154983. The next prime is 191155007. The reversal of 191154989 is 989451191.

It can be written as a sum of positive squares in 3 ways, for example, as 71690089 + 119464900 = 8467^2 + 10930^2 .

It is a de Polignac number, because none of the positive numbers 2^k-191154989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191154983) 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, 272339 + ... + 273039.

It is an arithmetic number, because the mean of its divisors is an integer number (31986695).

Almost surely, 2^191154989 is an apocalyptic number.

It is an amenable number.

191154989 is a deficient number, since it is larger than the sum of its proper divisors (765181).

191154989 is an frugal number, since it uses more digits than its factorization.

191154989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1791 (or 1090 counting only the distinct ones).

The product of its digits is 116640, while the sum is 47.

The square root of 191154989 is about 13825.8811292445. The cubic root of 191154989 is about 576.0522524051.

The spelling of 191154989 in words is "one hundred ninety-one million, one hundred fifty-four thousand, nine hundred eighty-nine".