1561015115 has 16 divisors (see below), whose sum is σ = 2069383680. Its totient is φ = 1120909920.

The previous prime is 1561015069. The next prime is 1561015139. The reversal of 1561015115 is 5115101651.

It is not a de Polignac number, because 1561015115 - 2⁸ = 1561014859 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, 175289 + ... + 183978.

It is an arithmetic number, because the mean of its divisors is an integer number (129336480).

Almost surely, 2^1561015115 is an apocalyptic number.

1561015115 is a deficient number, since it is larger than the sum of its proper divisors (508368565).

1561015115 is a wasteful number, since it uses less digits than its factorization.

1561015115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359362.

The product of its (nonzero) digits is 750, while the sum is 26.

The square root of 1561015115 is about 39509.6838129591. The cubic root of 1561015115 is about 1160.0295065324.

Adding to 1561015115 its reverse (5115101651), we get a palindrome (6676116766).

The spelling of 1561015115 in words is "one billion, five hundred sixty-one million, fifteen thousand, one hundred fifteen".