87128775 has 72 divisors (see below), whose sum is σ = 166842000. Its totient is φ = 43338240.

The previous prime is 87128771. The next prime is 87128777. The reversal of 87128775 is 57782178.

It is not a de Polignac number, because 87128775 - 2² = 87128771 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 87128775.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87128771) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 380361 + ... + 380589.

It is an arithmetic number, because the mean of its divisors is an integer number (2317250).

Almost surely, 2^87128775 is an apocalyptic number.

87128775 is a deficient number, since it is larger than the sum of its proper divisors (79713225).

87128775 is a wasteful number, since it uses less digits than its factorization.

87128775 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353 (or 345 counting only the distinct ones).

The product of its digits is 219520, while the sum is 45.

The square root of 87128775 is about 9334.2795651298. The cubic root of 87128775 is about 443.3232782061.

It can be divided in two parts, 871 and 28775, that added together give a triangular number (29646 = T₂₄₃).

The spelling of 87128775 in words is "eighty-seven million, one hundred twenty-eight thousand, seven hundred seventy-five".