135981643 has 4 divisors (see below), whose sum is σ = 155407600. Its totient is φ = 116555688.

The previous prime is 135981641. The next prime is 135981647. The reversal of 135981643 is 346189531.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 135981643 - 2¹ = 135981641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 135981596 and 135981605.

It is not an unprimeable number, because it can be changed into a prime (135981641) 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, 9712968 + ... + 9712981.

It is an arithmetic number, because the mean of its divisors is an integer number (38851900).

Almost surely, 2^135981643 is an apocalyptic number.

135981643 is a deficient number, since it is larger than the sum of its proper divisors (19425957).

135981643 is an equidigital number, since it uses as much as digits as its factorization.

135981643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19425956.

The product of its digits is 77760, while the sum is 40.

The square root of 135981643 is about 11661.1167132483. The cubic root of 135981643 is about 514.2331793375.

The spelling of 135981643 in words is "one hundred thirty-five million, nine hundred eighty-one thousand, six hundred forty-three".