85840813 has 2 divisors, whose sum is σ = 85840814. Its totient is φ = 85840812.

The previous prime is 85840801. The next prime is 85840819. The reversal of 85840813 is 31804858.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 85784644 + 56169 = 9262^2 + 237^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-85840813 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85840819) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42920406 + 42920407.

It is an arithmetic number, because the mean of its divisors is an integer number (42920407).

Almost surely, 2^85840813 is an apocalyptic number.

It is an amenable number.

85840813 is a deficient number, since it is larger than the sum of its proper divisors (1).

85840813 is an equidigital number, since it uses as much as digits as its factorization.

85840813 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 30720, while the sum is 37.

The square root of 85840813 is about 9265.0317322716. The cubic root of 85840813 is about 441.1279822157.

The spelling of 85840813 in words is "eighty-five million, eight hundred forty thousand, eight hundred thirteen".