135440561 has 2 divisors, whose sum is σ = 135440562. Its totient is φ = 135440560.

The previous prime is 135440549. The next prime is 135440563. The reversal of 135440561 is 165044531.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 127260961 + 8179600 = 11281^2 + 2860^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135440561 is a prime.

Together with 135440563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (135440563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67720280 + 67720281.

It is an arithmetic number, because the mean of its divisors is an integer number (67720281).

Almost surely, 2^135440561 is an apocalyptic number.

It is an amenable number.

135440561 is a deficient number, since it is larger than the sum of its proper divisors (1).

135440561 is an equidigital number, since it uses as much as digits as its factorization.

135440561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 29.

The square root of 135440561 is about 11637.8933231062. The cubic root of 135440561 is about 513.5502141505.

The spelling of 135440561 in words is "one hundred thirty-five million, four hundred forty thousand, five hundred sixty-one".