1361817565 has 4 divisors (see below), whose sum is σ = 1634181084. Its totient is φ = 1089454048.

The previous prime is 1361817553. The next prime is 1361817599. The reversal of 1361817565 is 5657181631.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5657181631 = 7993 ⋅707767.

It can be written as a sum of positive squares in 2 ways, for example, as 235745316 + 1126072249 = 15354^2 + 33557^2 .

It is a cyclic number.

It is not a de Polignac number, because 1361817565 - 2⁹ = 1361817053 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136181752 + ... + 136181761.

It is an arithmetic number, because the mean of its divisors is an integer number (408545271).

Almost surely, 2^1361817565 is an apocalyptic number.

It is an amenable number.

1361817565 is a deficient number, since it is larger than the sum of its proper divisors (272363519).

1361817565 is an equidigital number, since it uses as much as digits as its factorization.

1361817565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272363518.

The product of its digits is 151200, while the sum is 43.

The square root of 1361817565 is about 36902.8124266972. The cubic root of 1361817565 is about 1108.4249948250.

The spelling of 1361817565 in words is "one billion, three hundred sixty-one million, eight hundred seventeen thousand, five hundred sixty-five".