135225721 has 4 divisors (see below), whose sum is σ = 138102912. Its totient is φ = 132348532.

The previous prime is 135225719. The next prime is 135225767. The reversal of 135225721 is 127522531.

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 135225721 - 2¹ = 135225719 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 135225721.

It is not an unprimeable number, because it can be changed into a prime (135225791) 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, 1438525 + ... + 1438618.

It is an arithmetic number, because the mean of its divisors is an integer number (34525728).

Almost surely, 2^135225721 is an apocalyptic number.

It is an amenable number.

135225721 is a deficient number, since it is larger than the sum of its proper divisors (2877191).

135225721 is an equidigital number, since it uses as much as digits as its factorization.

135225721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2877190.

The product of its digits is 4200, while the sum is 28.

The square root of 135225721 is about 11628.6594670237. The cubic root of 135225721 is about 513.2785340483.

The spelling of 135225721 in words is "one hundred thirty-five million, two hundred twenty-five thousand, seven hundred twenty-one".