135601561 has 2 divisors, whose sum is σ = 135601562. Its totient is φ = 135601560.

The previous prime is 135601549. The next prime is 135601579. The reversal of 135601561 is 165106531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 95355225 + 40246336 = 9765^2 + 6344^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135601561 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (135601541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67800780 + 67800781.

It is an arithmetic number, because the mean of its divisors is an integer number (67800781).

Almost surely, 2^135601561 is an apocalyptic number.

It is an amenable number.

135601561 is a deficient number, since it is larger than the sum of its proper divisors (1).

135601561 is an equidigital number, since it uses as much as digits as its factorization.

135601561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2700, while the sum is 28.

The square root of 135601561 is about 11644.8083281778. The cubic root of 135601561 is about 513.7536215688.

The spelling of 135601561 in words is "one hundred thirty-five million, six hundred one thousand, five hundred sixty-one".