1561213115 has 32 divisors (see below), whose sum is σ = 2416296960. Its totient is φ = 939657600.

The previous prime is 1561213099. The next prime is 1561213141. The reversal of 1561213115 is 5113121651.

It is not a de Polignac number, because 1561213115 - 2⁴ = 1561213099 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 58751 + ... + 81080.

It is an arithmetic number, because the mean of its divisors is an integer number (75509280).

Almost surely, 2^1561213115 is an apocalyptic number.

1561213115 is a deficient number, since it is larger than the sum of its proper divisors (855083845).

1561213115 is a wasteful number, since it uses less digits than its factorization.

1561213115 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139883.

The product of its digits is 900, while the sum is 26.

The square root of 1561213115 is about 39512.1894483209. The cubic root of 1561213115 is about 1160.0785507152.

Adding to 1561213115 its reverse (5113121651), we get a palindrome (6674334766).

The spelling of 1561213115 in words is "one billion, five hundred sixty-one million, two hundred thirteen thousand, one hundred fifteen".