1561256 has 8 divisors (see below), whose sum is σ = 2927370. Its totient is φ = 780624.

The previous prime is 1561247. The next prime is 1561267. The reversal of 1561256 is 6521651.

It can be written as a sum of positive squares in only one way, i.e., 872356 + 688900 = 934^2 + 830^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an Ulam number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97571 + ... + 97586.

2^1561256 is an apocalyptic number.

It is an amenable number.

1561256 is a deficient number, since it is larger than the sum of its proper divisors (1366114).

1561256 is a wasteful number, since it uses less digits than its factorization.

1561256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195163 (or 195159 counting only the distinct ones).

The product of its digits is 1800, while the sum is 26.

The square root of 1561256 is about 1249.5023009182. The cubic root of 1561256 is about 116.0089172693.

The spelling of 1561256 in words is "one million, five hundred sixty-one thousand, two hundred fifty-six".