135208545991 has 4 divisors (see below), whose sum is σ = 135211182912. Its totient is φ = 135205909072.

The previous prime is 135208545971. The next prime is 135208546021. The reversal of 135208545991 is 199545802531.

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 135208545991 - 2¹⁷ = 135208414919 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 (135208545971) 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, 1239991 + ... + 1344616.

It is an arithmetic number, because the mean of its divisors is an integer number (33802795728).

Almost surely, 2^135208545991 is an apocalyptic number.

135208545991 is a deficient number, since it is larger than the sum of its proper divisors (2636921).

135208545991 is an equidigital number, since it uses as much as digits as its factorization.

135208545991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2636920.

The product of its (nonzero) digits is 1944000, while the sum is 52.

The spelling of 135208545991 in words is "one hundred thirty-five billion, two hundred eight million, five hundred forty-five thousand, nine hundred ninety-one".