1561266103 has 8 divisors (see below), whose sum is σ = 1599620400. Its totient is φ = 1523241408.

The previous prime is 1561266089. The next prime is 1561266131. The reversal of 1561266103 is 3016621651.

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

It is a cyclic number.

It is not a de Polignac number, because 1561266103 - 2⁵ = 1561266071 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561266193) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72798 + ... + 91771.

It is an arithmetic number, because the mean of its divisors is an integer number (199952550).

Almost surely, 2^1561266103 is an apocalyptic number.

1561266103 is a deficient number, since it is larger than the sum of its proper divisors (38354297).

1561266103 is a wasteful number, since it uses less digits than its factorization.

1561266103 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164801.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 1561266103 is about 39512.8599698883. The cubic root of 1561266103 is about 1160.0916750278.

Adding to 1561266103 its reverse (3016621651), we get a palindrome (4577887754).

The spelling of 1561266103 in words is "one billion, five hundred sixty-one million, two hundred sixty-six thousand, one hundred three".