85621 has 2 divisors, whose sum is σ = 85622. Its totient is φ = 85620.

The previous prime is 85619. The next prime is 85627. The reversal of 85621 is 12658.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 84100 + 1521 = 290^2 + 39^2 .

It is a cyclic number.

It is not a de Polignac number, because 85621 - 2¹ = 85619 is a prime.

Together with 85619, it forms a pair of twin primes.

It is a Chen prime.

85621 is a lucky number.

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 85592 and 85601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42810 + 42811.

It is an arithmetic number, because the mean of its divisors is an integer number (42811).

2⁸⁵⁶²¹ is an apocalyptic number.

It is an amenable number.

85621 is a deficient number, since it is larger than the sum of its proper divisors (1).

85621 is an equidigital number, since it uses as much as digits as its factorization.

85621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 480, while the sum is 22.

The square root of 85621 is about 292.6106628269. The cubic root of 85621 is about 44.0751127483.

The spelling of 85621 in words is "eighty-five thousand, six hundred twenty-one".