135021791 has 4 divisors (see below), whose sum is σ = 135099552. Its totient is φ = 134944032.

The previous prime is 135021787. The next prime is 135021797. The reversal of 135021791 is 197120531.

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 135021791 - 2² = 135021787 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 (135021797) 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, 36215 + ... + 39768.

It is an arithmetic number, because the mean of its divisors is an integer number (33774888).

Almost surely, 2^135021791 is an apocalyptic number.

135021791 is a deficient number, since it is larger than the sum of its proper divisors (77761).

135021791 is an equidigital number, since it uses as much as digits as its factorization.

135021791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77760.

The product of its (nonzero) digits is 1890, while the sum is 29.

The square root of 135021791 is about 11619.8877361186. The cubic root of 135021791 is about 513.0203840631.

The spelling of 135021791 in words is "one hundred thirty-five million, twenty-one thousand, seven hundred ninety-one".