85505831 has 4 divisors (see below), whose sum is σ = 87325152. Its totient is φ = 83686512.

The previous prime is 85505821. The next prime is 85505839. The reversal of 85505831 is 13850558.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85505831 is a prime.

It is a super-2 number, since 2×85505831² = 14622494270001122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 85505791 and 85505800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85505839) 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, 909590 + ... + 909683.

It is an arithmetic number, because the mean of its divisors is an integer number (21831288).

Almost surely, 2^85505831 is an apocalyptic number.

85505831 is a deficient number, since it is larger than the sum of its proper divisors (1819321).

85505831 is a wasteful number, since it uses less digits than its factorization.

85505831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1819320.

The product of its (nonzero) digits is 24000, while the sum is 35.

The square root of 85505831 is about 9246.9363034467. The cubic root of 85505831 is about 440.5534203662.

The spelling of 85505831 in words is "eighty-five million, five hundred five thousand, eight hundred thirty-one".