135776561 has 4 divisors (see below), whose sum is σ = 138665472. Its totient is φ = 132887652.

The previous prime is 135776551. The next prime is 135776587. The reversal of 135776561 is 165677531.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 135776561 - 2¹⁸ = 135514417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135776551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1444385 + ... + 1444478.

It is an arithmetic number, because the mean of its divisors is an integer number (34666368).

Almost surely, 2^135776561 is an apocalyptic number.

It is an amenable number.

135776561 is a deficient number, since it is larger than the sum of its proper divisors (2888911).

135776561 is an equidigital number, since it uses as much as digits as its factorization.

135776561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2888910.

The product of its digits is 132300, while the sum is 41.

The square root of 135776561 is about 11652.3199835913. The cubic root of 135776561 is about 513.9745340581.

The spelling of 135776561 in words is "one hundred thirty-five million, seven hundred seventy-six thousand, five hundred sixty-one".