1561431105 has 48 divisors (see below), whose sum is σ = 2918370000. Its totient is φ = 767729664.

The previous prime is 1561431101. The next prime is 1561431119. The reversal of 1561431105 is 5011341651.

1561431105 is a `hidden beast` number, since 1 + 5 + 614 + 31 + 10 + 5 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 493906176 + 1067524929 = 22224^2 + 32673^2 .

It is not a de Polignac number, because 1561431105 - 2² = 1561431101 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1561431101) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 729597 + ... + 731733.

It is an arithmetic number, because the mean of its divisors is an integer number (60799375).

Almost surely, 2^1561431105 is an apocalyptic number.

1561431105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561431105 is a deficient number, since it is larger than the sum of its proper divisors (1356938895).

1561431105 is a wasteful number, since it uses less digits than its factorization.

1561431105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3410 (or 3407 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 1561431105 is about 39514.9478678639. The cubic root of 1561431105 is about 1160.1325415833.

Adding to 1561431105 its reverse (5011341651), we get a palindrome (6572772756).

The spelling of 1561431105 in words is "one billion, five hundred sixty-one million, four hundred thirty-one thousand, one hundred five".