86978765 has 4 divisors (see below), whose sum is σ = 104374524. Its totient is φ = 69583008.

The previous prime is 86978761. The next prime is 86978807. The reversal of 86978765 is 56787968.

It is a happy number.

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 30713764 + 56265001 = 5542^2 + 7501^2 .

It is a cyclic number.

It is not a de Polignac number, because 86978765 - 2² = 86978761 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 86978765.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86978761) 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, 8697872 + ... + 8697881.

It is an arithmetic number, because the mean of its divisors is an integer number (26093631).

Almost surely, 2^86978765 is an apocalyptic number.

It is an amenable number.

86978765 is a deficient number, since it is larger than the sum of its proper divisors (17395759).

86978765 is a wasteful number, since it uses less digits than its factorization.

86978765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17395758.

The product of its digits is 5080320, while the sum is 56.

The square root of 86978765 is about 9326.2406681363. The cubic root of 86978765 is about 443.0687081645.

The spelling of 86978765 in words is "eighty-six million, nine hundred seventy-eight thousand, seven hundred sixty-five".