135721749 has 4 divisors (see below), whose sum is σ = 180962336. Its totient is φ = 90481164.

The previous prime is 135721739. The next prime is 135721757. The reversal of 135721749 is 947127531.

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 not a de Polignac number, because 135721749 - 2⁸ = 135721493 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135721739) 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, 22620289 + ... + 22620294.

It is an arithmetic number, because the mean of its divisors is an integer number (45240584).

Almost surely, 2^135721749 is an apocalyptic number.

It is an amenable number.

135721749 is a deficient number, since it is larger than the sum of its proper divisors (45240587).

135721749 is an equidigital number, since it uses as much as digits as its factorization.

135721749 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45240586.

The product of its digits is 52920, while the sum is 39.

The square root of 135721749 is about 11649.9677681958. The cubic root of 135721749 is about 513.9053621682.

The spelling of 135721749 in words is "one hundred thirty-five million, seven hundred twenty-one thousand, seven hundred forty-nine".