136605340021 has 2 divisors, whose sum is σ = 136605340022. Its totient is φ = 136605340020.

The previous prime is 136605339989. The next prime is 136605340033. The reversal of 136605340021 is 120043506631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 93180615025 + 43424724996 = 305255^2 + 208386^2 .

It is a cyclic number.

It is not a de Polignac number, because 136605340021 - 2⁵ = 136605339989 is a prime.

It is a super-2 number, since 2×136605340021² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136605340061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68302670010 + 68302670011.

It is an arithmetic number, because the mean of its divisors is an integer number (68302670011).

Almost surely, 2^136605340021 is an apocalyptic number.

It is an amenable number.

136605340021 is a deficient number, since it is larger than the sum of its proper divisors (1).

136605340021 is an equidigital number, since it uses as much as digits as its factorization.

136605340021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

Adding to 136605340021 its reverse (120043506631), we get a palindrome (256648846652).

The spelling of 136605340021 in words is "one hundred thirty-six billion, six hundred five million, three hundred forty thousand, twenty-one".