1561266304 has 64 divisors (see below), whose sum is σ = 3421031040. Its totient is φ = 705217536.

The previous prime is 1561266283. The next prime is 1561266307. The reversal of 1561266304 is 4036621651.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 1561266304.

It is not an unprimeable number, because it can be changed into a prime (1561266307) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68227 + ... + 88189.

It is an arithmetic number, because the mean of its divisors is an integer number (53453610).

Almost surely, 2^1561266304 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561266304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1710515520).

1561266304 is an abundant number, since it is smaller than the sum of its proper divisors (1859764736).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1561266304 is a wasteful number, since it uses less digits than its factorization.

1561266304 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20037 (or 20025 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 34.

The square root of 1561266304 is about 39512.8625133639. The cubic root of 1561266304 is about 1160.0917248118.

Adding to 1561266304 its reverse (4036621651), we get a palindrome (5597887955).

The spelling of 1561266304 in words is "one billion, five hundred sixty-one million, two hundred sixty-six thousand, three hundred four".