1561170123 has 12 divisors (see below), whose sum is σ = 2255366880. Its totient is φ = 1040621616.

The previous prime is 1561170109. The next prime is 1561170139. The reversal of 1561170123 is 3210711651.

It is not a de Polignac number, because 1561170123 - 2⁹ = 1561169611 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1561174123) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 103065 + ... + 117237.

It is an arithmetic number, because the mean of its divisors is an integer number (187947240).

Almost surely, 2^1561170123 is an apocalyptic number.

1561170123 is a deficient number, since it is larger than the sum of its proper divisors (694196757).

1561170123 is a wasteful number, since it uses less digits than its factorization.

1561170123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26418 (or 26415 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 27.

The square root of 1561170123 is about 39511.6454099295. The cubic root of 1561170123 is about 1160.0679020399.

Adding to 1561170123 its reverse (3210711651), we get a palindrome (4771881774).

The spelling of 1561170123 in words is "one billion, five hundred sixty-one million, one hundred seventy thousand, one hundred twenty-three".