135611321 has 4 divisors (see below), whose sum is σ = 137328000. Its totient is φ = 133894644.

The previous prime is 135611291. The next prime is 135611339. The reversal of 135611321 is 123116531.

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, and also an emirpimes, since its reverse is a distinct semiprime: 123116531 = 31 ⋅3971501.

It is a cyclic number.

It is not a de Polignac number, because 135611321 - 2¹⁴ = 135594937 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (135611351) 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, 858221 + ... + 858378.

It is an arithmetic number, because the mean of its divisors is an integer number (34332000).

Almost surely, 2^135611321 is an apocalyptic number.

It is an amenable number.

135611321 is a deficient number, since it is larger than the sum of its proper divisors (1716679).

135611321 is an equidigital number, since it uses as much as digits as its factorization.

135611321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1716678.

The product of its digits is 540, while the sum is 23.

The square root of 135611321 is about 11645.2273915111. The cubic root of 135611321 is about 513.7659471768.

Adding to 135611321 its reverse (123116531), we get a palindrome (258727852).

The spelling of 135611321 in words is "one hundred thirty-five million, six hundred eleven thousand, three hundred twenty-one".