87188991 has 8 divisors (see below), whose sum is σ = 117318960. Its totient is φ = 57592512.

The previous prime is 87188953. The next prime is 87188999. The reversal of 87188991 is 19988178.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 87188991 - 2¹¹ = 87186943 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87188999) 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 in 7 ways as a sum of consecutive naturals, for example, 132990 + ... + 133643.

It is an arithmetic number, because the mean of its divisors is an integer number (14664870).

Almost surely, 2^87188991 is an apocalyptic number.

87188991 is a deficient number, since it is larger than the sum of its proper divisors (30129969).

87188991 is a wasteful number, since it uses less digits than its factorization.

87188991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266745.

The product of its digits is 290304, while the sum is 51.

The square root of 87188991 is about 9337.5045381515. The cubic root of 87188991 is about 443.4253838043.

The spelling of 87188991 in words is "eighty-seven million, one hundred eighty-eight thousand, nine hundred ninety-one".