85236821 has 2 divisors, whose sum is σ = 85236822. Its totient is φ = 85236820.

The previous prime is 85236787. The next prime is 85236847. The reversal of 85236821 is 12863258.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62331025 + 22905796 = 7895^2 + 4786^2 .

It is a cyclic number.

It is not a de Polignac number, because 85236821 - 2¹⁸ = 84974677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85236881) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42618410 + 42618411.

It is an arithmetic number, because the mean of its divisors is an integer number (42618411).

Almost surely, 2^85236821 is an apocalyptic number.

It is an amenable number.

85236821 is a deficient number, since it is larger than the sum of its proper divisors (1).

85236821 is an equidigital number, since it uses as much as digits as its factorization.

85236821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 23040, while the sum is 35.

The square root of 85236821 is about 9232.3789458622. The cubic root of 85236821 is about 440.0909264566.

It can be divided in two parts, 852 and 36821, that added together give a palindrome (37673).

The spelling of 85236821 in words is "eighty-five million, two hundred thirty-six thousand, eight hundred twenty-one".