86136821 has 2 divisors, whose sum is σ = 86136822. Its totient is φ = 86136820.

The previous prime is 86136797. The next prime is 86136833. The reversal of 86136821 is 12863168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78127921 + 8008900 = 8839^2 + 2830^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-86136821 is a prime.

It is equal to p_5005979 and since 86136821 and 5005979 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86132821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43068410 + 43068411.

It is an arithmetic number, because the mean of its divisors is an integer number (43068411).

Almost surely, 2^86136821 is an apocalyptic number.

It is an amenable number.

86136821 is a deficient number, since it is larger than the sum of its proper divisors (1).

86136821 is an equidigital number, since it uses as much as digits as its factorization.

86136821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 35.

The square root of 86136821 is about 9280.9924577062. The cubic root of 86136821 is about 441.6344530597.

Adding to 86136821 its reverse (12863168), we get a palindrome (98999989).

The spelling of 86136821 in words is "eighty-six million, one hundred thirty-six thousand, eight hundred twenty-one".