1561497560 has 32 divisors (see below), whose sum is σ = 4015280160. Its totient is φ = 535370496.

The previous prime is 1561497551. The next prime is 1561497589. The reversal of 1561497560 is 657941651.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2788109 + ... + 2788668.

It is an arithmetic number, because the mean of its divisors is an integer number (125477505).

Almost surely, 2^1561497560 is an apocalyptic number.

1561497560 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1561497560 is an abundant number, since it is smaller than the sum of its proper divisors (2453782600).

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

1561497560 is a wasteful number, since it uses less digits than its factorization.

1561497560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5576795 (or 5576791 counting only the distinct ones).

The product of its (nonzero) digits is 226800, while the sum is 44.

The square root of 1561497560 is about 39515.7887432353. The cubic root of 1561497560 is about 1160.1489998854.

The spelling of 1561497560 in words is "one billion, five hundred sixty-one million, four hundred ninety-seven thousand, five hundred sixty".