135232991 has 4 divisors (see below), whose sum is σ = 135271512. Its totient is φ = 135194472.

The previous prime is 135232957. The next prime is 135232997. The reversal of 135232991 is 199232531.

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 135232991 - 2⁶ = 135232927 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 (135232997) 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, 13400 + ... + 21213.

It is an arithmetic number, because the mean of its divisors is an integer number (33817878).

Almost surely, 2^135232991 is an apocalyptic number.

135232991 is a deficient number, since it is larger than the sum of its proper divisors (38521).

135232991 is an equidigital number, since it uses as much as digits as its factorization.

135232991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38520.

The product of its digits is 14580, while the sum is 35.

The square root of 135232991 is about 11628.9720525935. The cubic root of 135232991 is about 513.2877321704.

It can be divided in two parts, 1352 and 32991, that added together give a palindrome (34343).

The spelling of 135232991 in words is "one hundred thirty-five million, two hundred thirty-two thousand, nine hundred ninety-one".