85439731 has 4 divisors (see below), whose sum is σ = 92012032. Its totient is φ = 78867432.

The previous prime is 85439723. The next prime is 85439741. The reversal of 85439731 is 13793458.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 85439731 - 2³ = 85439723 is a prime.

It is a super-2 number, since 2×85439731² = 14599895266704722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85439741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3286131 + ... + 3286156.

It is an arithmetic number, because the mean of its divisors is an integer number (23003008).

Almost surely, 2^85439731 is an apocalyptic number.

85439731 is a deficient number, since it is larger than the sum of its proper divisors (6572301).

85439731 is a wasteful number, since it uses less digits than its factorization.

85439731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6572300.

The product of its digits is 90720, while the sum is 40.

The square root of 85439731 is about 9243.3614556610. The cubic root of 85439731 is about 440.4398683124.

The spelling of 85439731 in words is "eighty-five million, four hundred thirty-nine thousand, seven hundred thirty-one".