86639645 has 4 divisors (see below), whose sum is σ = 103967580. Its totient is φ = 69311712.

The previous prime is 86639629. The next prime is 86639647. The reversal of 86639645 is 54693668.

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 27994681 + 58644964 = 5291^2 + 7658^2 .

It is a cyclic number.

It is not a de Polignac number, because 86639645 - 2⁴ = 86639629 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 86639645.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (86639647) 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, 8663960 + ... + 8663969.

It is an arithmetic number, because the mean of its divisors is an integer number (25991895).

Almost surely, 2^86639645 is an apocalyptic number.

It is an amenable number.

86639645 is a deficient number, since it is larger than the sum of its proper divisors (17327935).

86639645 is a wasteful number, since it uses less digits than its factorization.

86639645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17327934.

The product of its digits is 933120, while the sum is 47.

The square root of 86639645 is about 9308.0419530640. The cubic root of 86639645 is about 442.4921338787.

The spelling of 86639645 in words is "eighty-six million, six hundred thirty-nine thousand, six hundred forty-five".