135720409 has 4 divisors (see below), whose sum is σ = 148058640. Its totient is φ = 123382180.

The previous prime is 135720407. The next prime is 135720413. The reversal of 135720409 is 904027531.

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 135720409 - 2¹ = 135720407 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135720407) 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, 6169099 + ... + 6169120.

It is an arithmetic number, because the mean of its divisors is an integer number (37014660).

Almost surely, 2^135720409 is an apocalyptic number.

It is an amenable number.

135720409 is a deficient number, since it is larger than the sum of its proper divisors (12338231).

135720409 is a wasteful number, since it uses less digits than its factorization.

135720409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12338230.

The product of its (nonzero) digits is 7560, while the sum is 31.

The square root of 135720409 is about 11649.9102571651. The cubic root of 135720409 is about 513.9036708759.

The spelling of 135720409 in words is "one hundred thirty-five million, seven hundred twenty thousand, four hundred nine".