85381 has 2 divisors, whose sum is σ = 85382. Its totient is φ = 85380.

The previous prime is 85369. The next prime is 85411. The reversal of 85381 is 18358.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54756 + 30625 = 234^2 + 175^2 .

It is a cyclic number.

It is not a de Polignac number, because 85381 - 2⁹ = 84869 is a prime.

It is a super-2 number, since 2×85381² = 14579830322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42690 + 42691.

It is an arithmetic number, because the mean of its divisors is an integer number (42691).

2⁸⁵³⁸¹ is an apocalyptic number.

It is an amenable number.

85381 is a deficient number, since it is larger than the sum of its proper divisors (1).

85381 is an equidigital number, since it uses as much as digits as its factorization.

85381 is an evil number, because the sum of its binary digits is even.

The product of its digits is 960, while the sum is 25.

The square root of 85381 is about 292.2002737850. The cubic root of 85381 is about 44.0338926190.

It can be divided in two parts, 85 and 381, that multiplied together give a triangular number (32385 = T₂₅₄).

The spelling of 85381 in words is "eighty-five thousand, three hundred eighty-one".