87639191 has 8 divisors (see below), whose sum is σ = 92340480. Its totient is φ = 82946808.

The previous prime is 87639187. The next prime is 87639217. The reversal of 87639191 is 19193678.

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

It is a cyclic number.

It is not a de Polignac number, because 87639191 - 2² = 87639187 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 (87639121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30290 + ... + 33056.

It is an arithmetic number, because the mean of its divisors is an integer number (11542560).

Almost surely, 2^87639191 is an apocalyptic number.

87639191 is a deficient number, since it is larger than the sum of its proper divisors (4701289).

87639191 is a wasteful number, since it uses less digits than its factorization.

87639191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4453.

The product of its digits is 81648, while the sum is 44.

The square root of 87639191 is about 9361.5805823589. The cubic root of 87639191 is about 444.1872823397.

The spelling of 87639191 in words is "eighty-seven million, six hundred thirty-nine thousand, one hundred ninety-one".