87971570509 has 4 divisors (see below), whose sum is σ = 89631411516. Its totient is φ = 86311729504.

The previous prime is 87971570431. The next prime is 87971570563. The reversal of 87971570509 is 90507517978.

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 34977228484 + 52994342025 = 187022^2 + 230205^2 .

It is a cyclic number.

It is not a de Polignac number, because 87971570509 - 2¹³ = 87971562317 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87971570909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 829920424 + ... + 829920529.

It is an arithmetic number, because the mean of its divisors is an integer number (22407852879).

Almost surely, 2^87971570509 is an apocalyptic number.

It is an amenable number.

87971570509 is a deficient number, since it is larger than the sum of its proper divisors (1659841007).

87971570509 is a wasteful number, since it uses less digits than its factorization.

87971570509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659841006.

The product of its (nonzero) digits is 5556600, while the sum is 58.

The spelling of 87971570509 in words is "eighty-seven billion, nine hundred seventy-one million, five hundred seventy thousand, five hundred nine".