136620665 has 4 divisors (see below), whose sum is σ = 163944804. Its totient is φ = 109296528.

The previous prime is 136620643. The next prime is 136620683. The reversal of 136620665 is 566026631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 566026631 = 1949 ⋅290419.

It can be written as a sum of positive squares in 2 ways, for example, as 69822736 + 66797929 = 8356^2 + 8173^2 .

It is a cyclic number.

It is not a de Polignac number, because 136620665 - 2¹⁰ = 136619641 is a prime.

It is a super-2 number, since 2×136620665² = 37330412210084450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13662062 + ... + 13662071.

It is an arithmetic number, because the mean of its divisors is an integer number (40986201).

Almost surely, 2^136620665 is an apocalyptic number.

It is an amenable number.

136620665 is a deficient number, since it is larger than the sum of its proper divisors (27324139).

136620665 is an equidigital number, since it uses as much as digits as its factorization.

136620665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27324138.

The product of its (nonzero) digits is 38880, while the sum is 35.

The square root of 136620665 is about 11688.4842901037. The cubic root of 136620665 is about 515.0374371880.

The spelling of 136620665 in words is "one hundred thirty-six million, six hundred twenty thousand, six hundred sixty-five".