1561016408 has 128 divisors (see below), whose sum is σ = 3619123200. Its totient is φ = 616896000.

The previous prime is 1561016363. The next prime is 1561016419. The reversal of 1561016408 is 8046101651.

It is a congruent 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, 5084591 + ... + 5084897.

It is an arithmetic number, because the mean of its divisors is an integer number (28274400).

Almost surely, 2^1561016408 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 1561016408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1809561600).

1561016408 is an abundant number, since it is smaller than the sum of its proper divisors (2058106792).

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

1561016408 is a wasteful number, since it uses less digits than its factorization.

1561016408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 481 (or 477 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 1561016408 is about 39509.7001760327. The cubic root of 1561016408 is about 1160.0298268193.

The spelling of 1561016408 in words is "one billion, five hundred sixty-one million, sixteen thousand, four hundred eight".