135981217 has 4 divisors (see below), whose sum is σ = 136462000. Its totient is φ = 135500436.

The previous prime is 135981211. The next prime is 135981227. The reversal of 135981217 is 712189531.

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 135981217 - 2¹¹ = 135979169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135981211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239967 + ... + 240532.

It is an arithmetic number, because the mean of its divisors is an integer number (34115500).

Almost surely, 2^135981217 is an apocalyptic number.

It is an amenable number.

135981217 is a deficient number, since it is larger than the sum of its proper divisors (480783).

135981217 is an equidigital number, since it uses as much as digits as its factorization.

135981217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480782.

The product of its digits is 15120, while the sum is 37.

The square root of 135981217 is about 11661.0984474019. The cubic root of 135981217 is about 514.2326423445.

The spelling of 135981217 in words is "one hundred thirty-five million, nine hundred eighty-one thousand, two hundred seventeen".