136555561 has 2 divisors, whose sum is σ = 136555562. Its totient is φ = 136555560.

The previous prime is 136555547. The next prime is 136555583. The reversal of 136555561 is 165555631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131537961 + 5017600 = 11469^2 + 2240^2 .

It is a cyclic number.

It is not a de Polignac number, because 136555561 - 2²¹ = 134458409 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 136555561.

It is not a weakly prime, because it can be changed into another prime (136555511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68277780 + 68277781.

It is an arithmetic number, because the mean of its divisors is an integer number (68277781).

Almost surely, 2^136555561 is an apocalyptic number.

It is an amenable number.

136555561 is a deficient number, since it is larger than the sum of its proper divisors (1).

136555561 is an equidigital number, since it uses as much as digits as its factorization.

136555561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67500, while the sum is 37.

The square root of 136555561 is about 11685.6989949254. The cubic root of 136555561 is about 514.9556137320.

The spelling of 136555561 in words is "one hundred thirty-six million, five hundred fifty-five thousand, five hundred sixty-one".