136509971 has 4 divisors (see below), whose sum is σ = 147010752. Its totient is φ = 126009192.

The previous prime is 136509959. The next prime is 136509973. The reversal of 136509971 is 179905631.

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 136509971 - 2²⁶ = 69401107 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136509973) 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, 5250371 + ... + 5250396.

It is an arithmetic number, because the mean of its divisors is an integer number (36752688).

Almost surely, 2^136509971 is an apocalyptic number.

136509971 is a deficient number, since it is larger than the sum of its proper divisors (10500781).

136509971 is a wasteful number, since it uses less digits than its factorization.

136509971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10500780.

The product of its (nonzero) digits is 51030, while the sum is 41.

The square root of 136509971 is about 11683.7481571626. The cubic root of 136509971 is about 514.8983002122.

The spelling of 136509971 in words is "one hundred thirty-six million, five hundred nine thousand, nine hundred seventy-one".