1561335345 has 20 divisors (see below), whose sum is σ = 2798838900. Its totient is φ = 832711968.

The previous prime is 1561335341. The next prime is 1561335353. The reversal of 1561335345 is 5435331651.

1561335345 is a `hidden beast` number, since 1 + 5 + 613 + 3 + 5 + 34 + 5 = 666.

1561335345 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 1125736704 + 435598641 = 33552^2 + 20871^2 .

It is not a de Polignac number, because 1561335345 - 2² = 1561335341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1561335341) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1927170 + ... + 1927979.

It is an arithmetic number, because the mean of its divisors is an integer number (139941945).

Almost surely, 2^1561335345 is an apocalyptic number.

1561335345 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1561335345 is a deficient number, since it is larger than the sum of its proper divisors (1237503555).

1561335345 is an equidigital number, since it uses as much as digits as its factorization.

1561335345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3855166 (or 3855157 counting only the distinct ones).

The product of its digits is 81000, while the sum is 36.

The square root of 1561335345 is about 39513.7361559243. The cubic root of 1561335345 is about 1160.1088247586.

Adding to 1561335345 its reverse (5435331651), we get a palindrome (6996666996).

The spelling of 1561335345 in words is "one billion, five hundred sixty-one million, three hundred thirty-five thousand, three hundred forty-five".