1561265163 has 12 divisors (see below), whose sum is σ = 2255699160. Its totient is φ = 1040594976.

The previous prime is 1561265161. The next prime is 1561265177. The reversal of 1561265163 is 3615621651.

1561265163 is a `hidden beast` number, since 15 + 6 + 126 + 516 + 3 = 666.

It is not a de Polignac number, because 1561265163 - 2¹ = 1561265161 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1561265161) 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 11 ways as a sum of consecutive naturals, for example, 24220 + ... + 60902.

It is an arithmetic number, because the mean of its divisors is an integer number (187974930).

Almost surely, 2^1561265163 is an apocalyptic number.

1561265163 is a deficient number, since it is larger than the sum of its proper divisors (694433997).

1561265163 is a wasteful number, since it uses less digits than its factorization.

1561265163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41418 (or 41415 counting only the distinct ones).

The product of its digits is 32400, while the sum is 36.

The square root of 1561265163 is about 39512.8480750249. The cubic root of 1561265163 is about 1160.0914422068.

The spelling of 1561265163 in words is "one billion, five hundred sixty-one million, two hundred sixty-five thousand, one hundred sixty-three".