1581425 has 18 divisors (see below), whose sum is σ = 2110914. Its totient is φ = 1171200.

The previous prime is 1581421. The next prime is 1581431. The reversal of 1581425 is 5241851.

It can be written as a sum of positive squares in 9 ways, for example, as 1106704 + 474721 = 1052^2 + 689^2 .

It is not a de Polignac number, because 1581425 - 2² = 1581421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1581394 and 1581403.

It is not an unprimeable number, because it can be changed into a prime (1581421) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 25895 + ... + 25955.

It is an arithmetic number, because the mean of its divisors is an integer number (117273).

2^1581425 is an apocalyptic number.

It is an amenable number.

1581425 is a deficient number, since it is larger than the sum of its proper divisors (529489).

1581425 is an equidigital number, since it uses as much as digits as its factorization.

1581425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 149 (or 83 counting only the distinct ones).

The product of its digits is 1600, while the sum is 26.

The square root of 1581425 is about 1257.5472158134. The cubic root of 1581425 is about 116.5063330443.

The spelling of 1581425 in words is "one million, five hundred eighty-one thousand, four hundred twenty-five".