86138821 has 2 divisors, whose sum is σ = 86138822. Its totient is φ = 86138820.

The previous prime is 86138809. The next prime is 86138831. The reversal of 86138821 is 12883168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 62964225 + 23174596 = 7935^2 + 4814^2 .

It is a cyclic number.

It is not a de Polignac number, because 86138821 - 2⁷ = 86138693 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (86138831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43069410 + 43069411.

It is an arithmetic number, because the mean of its divisors is an integer number (43069411).

Almost surely, 2^86138821 is an apocalyptic number.

It is an amenable number.

86138821 is a deficient number, since it is larger than the sum of its proper divisors (1).

86138821 is an equidigital number, since it uses as much as digits as its factorization.

86138821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18432, while the sum is 37.

The square root of 86138821 is about 9281.1002041784. The cubic root of 86138821 is about 441.6378711182.

The spelling of 86138821 in words is "eighty-six million, one hundred thirty-eight thousand, eight hundred twenty-one".