1561560 has 192 divisors, whose sum is σ = 6324480. Its totient is φ = 299520.

The previous prime is 1561559. The next prime is 1561577. The reversal of 1561560 is 651651.

1561560 = T₂₉ + T₃₀ + ... + T₂₁₀.

1561560 = 25² + 26² + ... + 167².

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 1561560.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 120114 + ... + 120126.

It is an arithmetic number, because the mean of its divisors is an integer number (32940).

2^1561560 is an apocalyptic number.

1561560 is a gapful number since it is divisible by the number (10) 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 1561560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3162240).

1561560 is an abundant number, since it is smaller than the sum of its proper divisors (4762920).

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

1561560 is a wasteful number, since it uses less digits than its factorization.

1561560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58 (or 41 counting only the distinct ones).

The product of its (nonzero) digits is 900, while the sum is 24.

The square root of 1561560 is about 1249.6239434326. The cubic root of 1561560 is about 116.0164463404.

Subtracting from 1561560 its reverse (651651), we obtain a palindrome (909909).

The spelling of 1561560 in words is "one million, five hundred sixty-one thousand, five hundred sixty".