86140721 has 2 divisors, whose sum is σ = 86140722. Its totient is φ = 86140720.

The previous prime is 86140711. The next prime is 86140757. The reversal of 86140721 is 12704168.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76807696 + 9333025 = 8764^2 + 3055^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-86140721 is a prime.

It is equal to p_5006198 and since 86140721 and 5006198 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (86140711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43070360 + 43070361.

It is an arithmetic number, because the mean of its divisors is an integer number (43070361).

Almost surely, 2^86140721 is an apocalyptic number.

It is an amenable number.

86140721 is a deficient number, since it is larger than the sum of its proper divisors (1).

86140721 is an equidigital number, since it uses as much as digits as its factorization.

86140721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 86140721 is about 9281.2025621683. The cubic root of 86140721 is about 441.6411182247.

Adding to 86140721 its reverse (12704168), we get a palindrome (98844889).

The spelling of 86140721 in words is "eighty-six million, one hundred forty thousand, seven hundred twenty-one".