1561711104 has 100 divisors (see below), whose sum is σ = 4661420214. Its totient is φ = 520556544.

The previous prime is 1561711079. The next prime is 1561711111. The reversal of 1561711104 is 4011171651.

It can be written as a sum of positive squares in only one way, i.e., 1125736704 + 435974400 = 33552^2 + 20880^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 22644 + ... + 60300.

Almost surely, 2^1561711104 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 1561711104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2330710107).

1561711104 is an abundant number, since it is smaller than the sum of its proper divisors (3099709110).

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

1561711104 is an frugal number, since it uses more digits than its factorization.

1561711104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37687 (or 37662 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 27.

The square root of 1561711104 is about 39518.4906594369. The cubic root of 1561711104 is about 1160.2018832139.

Adding to 1561711104 its reverse (4011171651), we get a palindrome (5572882755).

The spelling of 1561711104 in words is "one billion, five hundred sixty-one million, seven hundred eleven thousand, one hundred four".