136664371534721 has 4 divisors (see below), whose sum is σ = 144703452213252. Its totient is φ = 128625290856192.

The previous prime is 136664371534711. The next prime is 136664371534763. The reversal of 136664371534721 is 127435173466631.

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

It can be written as a sum of positive squares in 2 ways, for example, as 73487944845121 + 63176426689600 = 8572511^2 + 7948360^2 .

It is not a de Polignac number, because 136664371534721 - 2⁴² = 132266325023617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (136664371534711) 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, 4019540339240 + ... + 4019540339273.

It is an arithmetic number, because the mean of its divisors is an integer number (36175863053313).

Almost surely, 2^{136664371534721} is an apocalyptic number.

It is an amenable number.

136664371534721 is a deficient number, since it is larger than the sum of its proper divisors (8039080678531).

136664371534721 is an equidigital number, since it uses as much as digits as its factorization.

136664371534721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8039080678530.

The product of its digits is 45722880, while the sum is 59.

The spelling of 136664371534721 in words is "one hundred thirty-six trillion, six hundred sixty-four billion, three hundred seventy-one million, five hundred thirty-four thousand, seven hundred twenty-one".