85164581 has 2 divisors, whose sum is σ = 85164582. Its totient is φ = 85164580.

The previous prime is 85164559. The next prime is 85164641. The reversal of 85164581 is 18546158.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 59752900 + 25411681 = 7730^2 + 5041^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85164581 is a prime.

It is a super-2 number, since 2×85164581² = 14506011713811122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85164181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42582290 + 42582291.

It is an arithmetic number, because the mean of its divisors is an integer number (42582291).

Almost surely, 2^85164581 is an apocalyptic number.

It is an amenable number.

85164581 is a deficient number, since it is larger than the sum of its proper divisors (1).

85164581 is an equidigital number, since it uses as much as digits as its factorization.

85164581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 38400, while the sum is 38.

The square root of 85164581 is about 9228.4657988205. The cubic root of 85164581 is about 439.9665625417.

The spelling of 85164581 in words is "eighty-five million, one hundred sixty-four thousand, five hundred eighty-one".