1561534145 has 16 divisors (see below), whose sum is σ = 1963008000. Its totient is φ = 1190874048.

The previous prime is 1561534129. The next prime is 1561534153. The reversal of 1561534145 is 5414351651.

It is a cyclic number.

It is not a de Polignac number, because 1561534145 - 2⁴ = 1561534129 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56705 + ... + 79614.

It is an arithmetic number, because the mean of its divisors is an integer number (122688000).

Almost surely, 2^1561534145 is an apocalyptic number.

It is an amenable number.

1561534145 is a deficient number, since it is larger than the sum of its proper divisors (401473855).

1561534145 is a wasteful number, since it uses less digits than its factorization.

1561534145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136432.

The product of its digits is 36000, while the sum is 35.

The square root of 1561534145 is about 39516.2516567551. The cubic root of 1561534145 is about 1160.1580603584.

Adding to 1561534145 its reverse (5414351651), we get a palindrome (6975885796).

The spelling of 1561534145 in words is "one billion, five hundred sixty-one million, five hundred thirty-four thousand, one hundred forty-five".