1561421316 has 96 divisors (see below), whose sum is σ = 4504550400. Its totient is φ = 409924224.

The previous prime is 1561421227. The next prime is 1561421339. The reversal of 1561421316 is 6131241651.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 244735 + ... + 251033.

It is an arithmetic number, because the mean of its divisors is an integer number (46922400).

Almost surely, 2^1561421316 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 1561421316, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2252275200).

1561421316 is an abundant number, since it is smaller than the sum of its proper divisors (2943129084).

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

1561421316 is a wasteful number, since it uses less digits than its factorization.

1561421316 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6553 (or 6551 counting only the distinct ones).

The product of its digits is 4320, while the sum is 30.

The square root of 1561421316 is about 39514.8240031510. The cubic root of 1561421316 is about 1160.1301171918.

Adding to 1561421316 its reverse (6131241651), we get a palindrome (7692662967).

The spelling of 1561421316 in words is "one billion, five hundred sixty-one million, four hundred twenty-one thousand, three hundred sixteen".