1581225 has 24 divisors (see below), whose sum is σ = 2708160. Its totient is φ = 813120.

The previous prime is 1581211. The next prime is 1581257. The reversal of 1581225 is 5221851.

It is not a de Polignac number, because 1581225 - 2⁵ = 1581193 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1581195 and 1581204.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1812 + ... + 2538.

It is an arithmetic number, because the mean of its divisors is an integer number (112840).

2^1581225 is an apocalyptic number.

1581225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1581225 is a deficient number, since it is larger than the sum of its proper divisors (1126935).

1581225 is a wasteful number, since it uses less digits than its factorization.

1581225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 769 (or 764 counting only the distinct ones).

The product of its digits is 800, while the sum is 24.

The square root of 1581225 is about 1257.4676934220. The cubic root of 1581225 is about 116.5014213879.

The spelling of 1581225 in words is "one million, five hundred eighty-one thousand, two hundred twenty-five".