86787989 has 4 divisors (see below), whose sum is σ = 86807820. Its totient is φ = 86768160.

The previous prime is 86787983. The next prime is 86788001. The reversal of 86787989 is 98978768.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35307364 + 51480625 = 5942^2 + 7175^2 .

It is a cyclic number.

It is not a de Polignac number, because 86787989 - 2⁴ = 86787973 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 (86787983) 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 3 ways as a sum of consecutive naturals, for example, 134 + ... + 13175.

It is an arithmetic number, because the mean of its divisors is an integer number (21701955).

Almost surely, 2^86787989 is an apocalyptic number.

It is an amenable number.

86787989 is a deficient number, since it is larger than the sum of its proper divisors (19831).

86787989 is a wasteful number, since it uses less digits than its factorization.

86787989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19830.

The product of its digits is 12192768, while the sum is 62.

The square root of 86787989 is about 9316.0071382540. The cubic root of 86787989 is about 442.7445342099.

The spelling of 86787989 in words is "eighty-six million, seven hundred eighty-seven thousand, nine hundred eighty-nine".