1561550065 has 8 divisors (see below), whose sum is σ = 1881327168. Its totient is φ = 1244262000.

The previous prime is 1561550009. The next prime is 1561550071. The reversal of 1561550065 is 5600551651.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1561550065 - 2¹³ = 1561541873 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1561550065.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 620877 + ... + 623386.

It is an arithmetic number, because the mean of its divisors is an integer number (235165896).

Almost surely, 2^1561550065 is an apocalyptic number.

It is an amenable number.

1561550065 is a deficient number, since it is larger than the sum of its proper divisors (319777103).

1561550065 is a wasteful number, since it uses less digits than its factorization.

1561550065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1244519.

The product of its (nonzero) digits is 22500, while the sum is 34.

The square root of 1561550065 is about 39516.4530923513. The cubic root of 1561550065 is about 1160.1620029883.

The spelling of 1561550065 in words is "one billion, five hundred sixty-one million, five hundred fifty thousand, sixty-five".