135640691 has 4 divisors (see below), whose sum is σ = 135672384. Its totient is φ = 135609000.

The previous prime is 135640657. The next prime is 135640693. The reversal of 135640691 is 196046531.

135640691 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135640691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (135640693) 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, 8195 + ... + 18396.

It is an arithmetic number, because the mean of its divisors is an integer number (33918096).

Almost surely, 2^135640691 is an apocalyptic number.

135640691 is a deficient number, since it is larger than the sum of its proper divisors (31693).

135640691 is an equidigital number, since it uses as much as digits as its factorization.

135640691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31692.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 135640691 is about 11646.4883548647. The cubic root of 135640691 is about 513.8030340920.

The spelling of 135640691 in words is "one hundred thirty-five million, six hundred forty thousand, six hundred ninety-one".