87581765 has 8 divisors (see below), whose sum is σ = 105330840. Its totient is φ = 69910272.

The previous prime is 87581761. The next prime is 87581801. The reversal of 87581765 is 56718578.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 21224449 + 66357316 = 4607^2 + 8146^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 87581765 - 2² = 87581761 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87581761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16880 + ... + 21449.

It is an arithmetic number, because the mean of its divisors is an integer number (13166355).

Almost surely, 2^87581765 is an apocalyptic number.

It is an amenable number.

87581765 is a deficient number, since it is larger than the sum of its proper divisors (17749075).

87581765 is a wasteful number, since it uses less digits than its factorization.

87581765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38791.

The product of its digits is 470400, while the sum is 47.

The square root of 87581765 is about 9358.5129694840. The cubic root of 87581765 is about 444.0902425260.

The spelling of 87581765 in words is "eighty-seven million, five hundred eighty-one thousand, seven hundred sixty-five".