8636215981 has 2 divisors, whose sum is σ = 8636215982. Its totient is φ = 8636215980.

The previous prime is 8636215967. The next prime is 8636216011. The reversal of 8636215981 is 1895126368.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6318660100 + 2317555881 = 79490^2 + 48141^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8636215981 is a prime.

It is a super-2 number, since 2×8636215981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8636213981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4318107990 + 4318107991.

It is an arithmetic number, because the mean of its divisors is an integer number (4318107991).

Almost surely, 2^8636215981 is an apocalyptic number.

It is an amenable number.

8636215981 is a deficient number, since it is larger than the sum of its proper divisors (1).

8636215981 is an equidigital number, since it uses as much as digits as its factorization.

8636215981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 622080, while the sum is 49.

The square root of 8636215981 is about 92931.2432984731. The cubic root of 8636215981 is about 2051.6715283115.

The spelling of 8636215981 in words is "eight billion, six hundred thirty-six million, two hundred fifteen thousand, nine hundred eighty-one".