1561060816 has 60 divisors (see below), whose sum is σ = 3526868388. Its totient is φ = 667408896.

The previous prime is 1561060811. The next prime is 1561060817. The reversal of 1561060816 is 6180601651.

It can be written as a sum of positive squares in 2 ways, for example, as 1497380416 + 63680400 = 38696^2 + 7980^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561060811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 356110 + ... + 360466.

Almost surely, 2^1561060816 is an apocalyptic number.

1561060816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1561060816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1763434194).

1561060816 is an abundant number, since it is smaller than the sum of its proper divisors (1965807572).

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

1561060816 is a wasteful number, since it uses less digits than its factorization.

1561060816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4836 (or 4823 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 34.

The square root of 1561060816 is about 39510.2621606083. The cubic root of 1561060816 is about 1160.0408269420.

The spelling of 1561060816 in words is "one billion, five hundred sixty-one million, sixty thousand, eight hundred sixteen".