1561856 has 18 divisors (see below), whose sum is σ = 3118122. Its totient is φ = 780800.

The previous prime is 1561829. The next prime is 1561883. The reversal of 1561856 is 6581651.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (1561829) and next prime (1561883).

It can be written as a sum of positive squares in only one way, i.e., 1401856 + 160000 = 1184^2 + 400^2 .

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2795 + ... + 3306.

It is an arithmetic number, because the mean of its divisors is an integer number (173229).

2^1561856 is an apocalyptic number.

1561856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1561856 is a deficient number, since it is larger than the sum of its proper divisors (1556266).

1561856 is an frugal number, since it uses more digits than its factorization.

1561856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6117 (or 6103 counting only the distinct ones).

The product of its digits is 7200, while the sum is 32.

The square root of 1561856 is about 1249.7423734514. The cubic root of 1561856 is about 116.0237763391.

The spelling of 1561856 in words is "one million, five hundred sixty-one thousand, eight hundred fifty-six".