135705989 has 4 divisors (see below), whose sum is σ = 135846720. Its totient is φ = 135565260.

The previous prime is 135705937. The next prime is 135705991. The reversal of 135705989 is 989507531.

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, and also an emirpimes, since its reverse is a distinct semiprime: 989507531 = 5869 ⋅168599.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135705989 is a prime.

It is a super-2 number, since 2×135705989² = 36832230900936242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (135705919) 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, 68909 + ... + 70850.

It is an arithmetic number, because the mean of its divisors is an integer number (33961680).

Almost surely, 2^135705989 is an apocalyptic number.

It is an amenable number.

135705989 is a deficient number, since it is larger than the sum of its proper divisors (140731).

135705989 is an equidigital number, since it uses as much as digits as its factorization.

135705989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140730.

The product of its (nonzero) digits is 340200, while the sum is 47.

The square root of 135705989 is about 11649.2913518377. The cubic root of 135705989 is about 513.8854698467.

The spelling of 135705989 in words is "one hundred thirty-five million, seven hundred five thousand, nine hundred eighty-nine".