136818661 has 4 divisors (see below), whose sum is σ = 156364192. Its totient is φ = 117273132.

The previous prime is 136818659. The next prime is 136818679. The reversal of 136818661 is 166818631.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 166818631 = 7 ⋅23831233.

It is a cyclic number.

It is not a de Polignac number, because 136818661 - 2¹ = 136818659 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 (136818631) 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, 9772755 + ... + 9772768.

It is an arithmetic number, because the mean of its divisors is an integer number (39091048).

Almost surely, 2^136818661 is an apocalyptic number.

It is an amenable number.

136818661 is a deficient number, since it is larger than the sum of its proper divisors (19545531).

136818661 is an equidigital number, since it uses as much as digits as its factorization.

136818661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19545530.

The product of its digits is 41472, while the sum is 40.

The square root of 136818661 is about 11696.9509274853. The cubic root of 136818661 is about 515.2861212111.

The spelling of 136818661 in words is "one hundred thirty-six million, eight hundred eighteen thousand, six hundred sixty-one".