135215321 has 4 divisors (see below), whose sum is σ = 141094272. Its totient is φ = 129336372.

The previous prime is 135215317. The next prime is 135215329. The reversal of 135215321 is 123512531.

It is a happy number.

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 135215321 - 2² = 135215317 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 5878927 = 135215321 / (1 + 3 + 5 + 2 + 1 + 5 + 3 + 2 + 1).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135215329) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2939441 + ... + 2939486.

It is an arithmetic number, because the mean of its divisors is an integer number (35273568).

Almost surely, 2^135215321 is an apocalyptic number.

It is an amenable number.

135215321 is a deficient number, since it is larger than the sum of its proper divisors (5878951).

135215321 is an equidigital number, since it uses as much as digits as its factorization.

135215321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5878950.

The product of its digits is 900, while the sum is 23.

The square root of 135215321 is about 11628.2122873639. The cubic root of 135215321 is about 513.2653752263.

Adding to 135215321 its reverse (123512531), we get a palindrome (258727852).

The spelling of 135215321 in words is "one hundred thirty-five million, two hundred fifteen thousand, three hundred twenty-one".