85547821 has 2 divisors, whose sum is σ = 85547822. Its totient is φ = 85547820.

The previous prime is 85547809. The next prime is 85547837. The reversal of 85547821 is 12874558.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 69056100 + 16491721 = 8310^2 + 4061^2 .

It is a cyclic number.

It is not a de Polignac number, because 85547821 - 2²¹ = 83450669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85547801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42773910 + 42773911.

It is an arithmetic number, because the mean of its divisors is an integer number (42773911).

Almost surely, 2^85547821 is an apocalyptic number.

It is an amenable number.

85547821 is a deficient number, since it is larger than the sum of its proper divisors (1).

85547821 is an equidigital number, since it uses as much as digits as its factorization.

85547821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 89600, while the sum is 40.

The square root of 85547821 is about 9249.2065065064. The cubic root of 85547821 is about 440.6255238731.

It can be divided in two parts, 85547 and 821, that added together give a palindrome (86368).

The spelling of 85547821 in words is "eighty-five million, five hundred forty-seven thousand, eight hundred twenty-one".