1561144104 has 160 divisors (see below), whose sum is σ = 4810417920. Its totient is φ = 470012544.

The previous prime is 1561144099. The next prime is 1561144127. The reversal of 1561144104 is 4014411651.

1561144104 is a `hidden beast` number, since 1 + 5 + 611 + 4 + 41 + 0 + 4 = 666.

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 39 ways as a sum of consecutive naturals, for example, 393957 + ... + 397899.

It is an arithmetic number, because the mean of its divisors is an integer number (30065112).

Almost surely, 2^1561144104 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 1561144104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2405208960).

1561144104 is an abundant number, since it is smaller than the sum of its proper divisors (3249273816).

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

1561144104 is a wasteful number, since it uses less digits than its factorization.

1561144104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4021 (or 4008 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 1561144104 is about 39511.3161511990. The cubic root of 1561144104 is about 1160.0614573067.

Adding to 1561144104 its reverse (4014411651), we get a palindrome (5575555755).

The spelling of 1561144104 in words is "one billion, five hundred sixty-one million, one hundred forty-four thousand, one hundred four".