1561600 has 66 divisors (see below), whose sum is σ = 3934334. Its totient is φ = 614400.

The previous prime is 1561597. The next prime is 1561601. The reversal of 1561600 is 61651.

It can be written as a sum of positive squares in 3 ways, for example, as 4096 + 1557504 = 64^2 + 1248^2 .

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1561601) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 25570 + ... + 25630.

2^1561600 is an apocalyptic number.

1561600 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 1561600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1967167).

1561600 is an abundant number, since it is smaller than the sum of its proper divisors (2372734).

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

1561600 is an equidigital number, since it uses as much as digits as its factorization.

1561600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 68 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1561600 is about 1249.6399481451. The cubic root of 1561600 is about 116.0174369349.

The spelling of 1561600 in words is "one million, five hundred sixty-one thousand, six hundred".