1581256 has 32 divisors (see below), whose sum is σ = 3182400. Its totient is φ = 734400.

The previous prime is 1581211. The next prime is 1581257. The reversal of 1581256 is 6521851.

It is an Ulam number.

It is not an unprimeable number, because it can be changed into a prime (1581257) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15301 + ... + 15403.

It is an arithmetic number, because the mean of its divisors is an integer number (99450).

2^1581256 is an apocalyptic number.

It is an amenable number.

1581256 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

1581256 is a wasteful number, since it uses less digits than its factorization.

1581256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 225 counting only the distinct ones).

The product of its digits is 2400, while the sum is 28.

The square root of 1581256 is about 1257.4800197220. The cubic root of 1581256 is about 116.5021827217.

The spelling of 1581256 in words is "one million, five hundred eighty-one thousand, two hundred fifty-six".