87855871573 has 4 divisors (see below), whose sum is σ = 87856641580. Its totient is φ = 87855101568.

The previous prime is 87855871567. The next prime is 87855871583. The reversal of 87855871573 is 37517855878.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 32170727044 + 55685144529 = 179362^2 + 235977^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87855871573 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 (87855871553) 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, 176058 + ... + 454651.

It is an arithmetic number, because the mean of its divisors is an integer number (21964160395).

Almost surely, 2^87855871573 is an apocalyptic number.

It is an amenable number.

87855871573 is a deficient number, since it is larger than the sum of its proper divisors (770007).

87855871573 is a wasteful number, since it uses less digits than its factorization.

87855871573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770006.

The product of its digits is 65856000, while the sum is 64.

It can be divided in two parts, 878558 and 71573, that added together give a triangular number (950131 = T₁₃₇₈).

The spelling of 87855871573 in words is "eighty-seven billion, eight hundred fifty-five million, eight hundred seventy-one thousand, five hundred seventy-three".