85731578 has 8 divisors (see below), whose sum is σ = 136161972. Its totient is φ = 40344256.

The previous prime is 85731563. The next prime is 85731589. The reversal of 85731578 is 87513758.

It can be written as a sum of positive squares in 2 ways, for example, as 85618009 + 113569 = 9253^2 + 337^2 .

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

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1260725 + ... + 1260792.

Almost surely, 2^85731578 is an apocalyptic number.

85731578 is a deficient number, since it is larger than the sum of its proper divisors (50430394).

85731578 is a wasteful number, since it uses less digits than its factorization.

85731578 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2521536.

The product of its digits is 235200, while the sum is 44.

The square root of 85731578 is about 9259.1348407937. The cubic root of 85731578 is about 440.9407866089.

The spelling of 85731578 in words is "eighty-five million, seven hundred thirty-one thousand, five hundred seventy-eight".