87191189 has 4 divisors (see below), whose sum is σ = 90003840. Its totient is φ = 84378540.

The previous prime is 87191177. The next prime is 87191207. The reversal of 87191189 is 98119178.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 98119178 = 2 ⋅49059589.

It is a cyclic number.

It is not a de Polignac number, because 87191189 - 2⁴ = 87191173 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 (87191119) 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, 1406279 + ... + 1406340.

It is an arithmetic number, because the mean of its divisors is an integer number (22500960).

Almost surely, 2^87191189 is an apocalyptic number.

It is an amenable number.

87191189 is a deficient number, since it is larger than the sum of its proper divisors (2812651).

87191189 is a wasteful number, since it uses less digits than its factorization.

87191189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2812650.

The product of its digits is 36288, while the sum is 44.

The square root of 87191189 is about 9337.6222348090. The cubic root of 87191189 is about 443.4291099659.

The spelling of 87191189 in words is "eighty-seven million, one hundred ninety-one thousand, one hundred eighty-nine".