61618565 has 4 divisors (see below), whose sum is σ = 73942284. Its totient is φ = 49294848.

The previous prime is 61618553. The next prime is 61618567. The reversal of 61618565 is 56581616.

61618565 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 can be written as a sum of positive squares in 2 ways, for example, as 25989604 + 35628961 = 5098^2 + 5969^2 .

It is a cyclic number.

It is not a de Polignac number, because 61618565 - 2⁴ = 61618549 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61618567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6161852 + ... + 6161861.

It is an arithmetic number, because the mean of its divisors is an integer number (18485571).

Almost surely, 2^61618565 is an apocalyptic number.

It is an amenable number.

61618565 is a deficient number, since it is larger than the sum of its proper divisors (12323719).

61618565 is a wasteful number, since it uses less digits than its factorization.

61618565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12323718.

The product of its digits is 43200, while the sum is 38.

The square root of 61618565 is about 7849.7493590560. The cubic root of 61618565 is about 394.9758357273.

The spelling of 61618565 in words is "sixty-one million, six hundred eighteen thousand, five hundred sixty-five".