136243021 has 2 divisors, whose sum is σ = 136243022. Its totient is φ = 136243020.

The previous prime is 136242973. The next prime is 136243043. The reversal of 136243021 is 120342631.

It is an a-pointer prime, because the next prime (136243043) can be obtained adding 136243021 to its sum of digits (22).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 101727396 + 34515625 = 10086^2 + 5875^2 .

It is a cyclic number.

It is not a de Polignac number, because 136243021 - 2¹³ = 136234829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 136242983 and 136243001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136243621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68121510 + 68121511.

It is an arithmetic number, because the mean of its divisors is an integer number (68121511).

Almost surely, 2^136243021 is an apocalyptic number.

It is an amenable number.

136243021 is a deficient number, since it is larger than the sum of its proper divisors (1).

136243021 is an equidigital number, since it uses as much as digits as its factorization.

136243021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 136243021 is about 11672.3185785858. The cubic root of 136243021 is about 514.5624473434.

Adding to 136243021 its reverse (120342631), we get a palindrome (256585652).

The spelling of 136243021 in words is "one hundred thirty-six million, two hundred forty-three thousand, twenty-one".